# 6.5 credmore versus .260 rem on ar



## hooktender

would like to hear coments on all aspects and reomendations


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## xdeano

They're a horse a piece, to be honest. 
xdeano


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## barebackjack

Yup.

Flip a coin or eenie meenie minie mo it.

Neither caliber will be able to achieve its full velocity potential in an AR, but thats the gun not the caliber.


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## Savage260

The 6.5C brass is much harder to find than the 260 brass. That was the major factor in me getting the DPMS LR260.-


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## knutson24

barebackjack said:


> Yup.
> 
> Flip a coin or eenie meenie minie mo it.
> 
> Neither caliber will be able to achieve its full velocity potential in an AR, but thats the gun not the caliber.


Not trying to stir the pot or anyting, but why would an AR platform prevent you from reaching each calibers potential velocity?

Knutson


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## xdeano

The only think I can think of is barrel length. Most AR platforms have relatively short barrels and utilize a 1-8.5" twist. So you wouldn't be able to spin heavier/higher BC bullets as well and with the shorter barrel length you won't have the extra 50-100fps or so.

My only issue with the AR platforms and shooting hard to get brass such as the Creedmore is that you'll have a hell of a time finding the brass in tall grass if you are using it for hunting etc. At the range with a catcher is a different story. Also in most cases the brass will hit the assist ramp and dent the brass, which doesn't hurt it, except for reloading it, you'll end up with a cosmetic flaw, not to big a deal.

I'd say if you want to get the most out of a case either get a barrel with a faster twist, unless you're shooting 123g bullets or smaller and get a longer barrel. Or just get a bolt action so you can find your brass at the end of the day.

xdeano


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## barebackjack

knutson24 said:


> barebackjack said:
> 
> 
> 
> Yup.
> 
> Flip a coin or eenie meenie minie mo it.
> 
> Neither caliber will be able to achieve its full velocity potential in an AR, but thats the gun not the caliber.
> 
> 
> 
> Not trying to stir the pot or anyting, but why would an AR platform prevent you from reaching each calibers potential velocity?
> 
> Knutson
Click to expand...

Shorter barrels typically and the correlation to ft/lbs required to operate the bolt.
Gas ops are using gas from fired round to operate the action, whereas a bolt is using it all for bullet pushing.

Most 6.5mm gas ops are shooting 100 fps slower than a bolt gun (all else being equal).

The .260 (and other 6.5s) from what I hear is more sensitive to barrel length than other calibers as it pertains to muzzle velocity. Anything below 23-24" and velocity really suffers. Its a caliber that likes slow powders, and slow powders do better in longer barrels.

A .308 can still obtain some dandy speeds in an 18-20" barrel, the .260 not so much.

That being said, you may be able to match bolt speeds in a gas op, each rifle is its own beast. You can take to "identical" rifles and have pressure signs in one well before the other. But most of what I hear of the .260 in a gas op is around that 100 fps slower mark.


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## knutson24

Thats what I figured it probably was but wasn' sure. So figuratively speaking with an adjustable gas block set to the off position forcing you to operate the bolt manually would most like yield the same velocities with everything else being equal?


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## mr.trooper

I understand why people like 6.5 cartridges... but this new glut of them is silly.

If I recall correctly, both 6.5C and 260 are just 308's necked down to 26 caliber. They even have the same case capacity.

The silly thing is the old 6.5x55 actually has a little more capacity than both of them, and in modern rifles it can be loaded to the same pressures - that means it can outstrip both of its competitors when using heavy bullets. Often imitated, never duplicated.


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## Savage260

" but this new glut of them is silly."

Or brilliant, depending on who you are talking to. The popularity of the 6.5s has definately skyrocketed due to people winning matches with them, the BC and bullet types available.

As far as the 6.5X55 all my loading books show it to be equal or just below the 6.5 and 260. I understand what you are saying about the "modern" firearms, and that is why I would like to see some published data on what it can really do. I have never seen or even know any one that has a modern 6.5X55. Although I would like to shoot one some time.

Definately wouldn't get that case into most AR platforms, which was the point of the thread, and the 6.5C and 260 are basically just as good as the 6.5X55 and on a short action, which gets the nod in my book. I suppose you can always throw the 6.5X55 in a short action and use it as a single shot, and pull the bolt if you want to eject a live round. Major mods would have to be made in order to extend the magazine to allow LA lengths to be loaded to also, so that would cut powder capacity way down below the other two any way.


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## barebackjack

mr.trooper said:


> I understand why people like 6.5 cartridges... but this new glut of them is silly.
> 
> If I recall correctly, both 6.5C and 260 are just 308's necked down to 26 caliber. They even have the same case capacity.
> 
> The silly thing is the old 6.5x55 actually has a little more capacity than both of them, and in modern rifles it can be loaded to the same pressures - that means it can outstrip both of its competitors when using heavy bullets. Often imitated, never duplicated.


Actually, the .260 Rem isnt really that "new".

Jim Carmicheal or one of those big gun writers (I cant remember specifically what one) was writing about the advantages of a .308 necked to 6.5mm back in the 70's already.

It is "new" for being commercially chambered in factory rifles, 1997 or '98 I believe.


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## KRAKMT

Technically the 6.5 Creedmore is not new either. 
Parent case is the 250 savage with a few changes. 
Decision will depend on the bullet/coal combo desired.
K


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## CV-580

"Most AR platforms have... and utilize a 1-8.5" twist."

Internet BS.

"xdeano", do you even own an AR rifle of ANY type?

Own more than a few, that I actually use and shoot and NOT one has a 1:8.5" twist, regardless of the cartridge or caliber, NOT one.

Far more common are 1:7, 1:8, 1:9 or 1:12 for the .223R and 1:10 for the AR-10 "types". Even my Satern barreled 6.5 Grendels have a 1:8.75" twist, close to 1:8.5" but still NOT 1:8.5".

I'll let the wanna-be internet experts proclaim which is most popular, hopefully one of the real experts on here will know.

"So you wouldn't be able to spin heavier/higher BC bullets as well..."

How much heavier than 77g and 80g bullets do you want to shoot out of a 16" barrel?

"...and with the shorter barrel length you won't have the extra 50-100fps or so."

Your target will NEVER know the difference and if you think 50-100 fps (at the muzzle) is going to matter you are just kidding yourself.

"...and shooting hard to get brass such as the Creedmore..."

When is the last time you have tried to buy 6.5 Creedmore brass, I'll bet NEVER!

"I'd say if you want to get the most out of a case either get a barrel with a faster twist..."

Physical law... It takes MORE energy to spin a bullet faster. With all other factors equal, increasing the twist rate will DECREASE velocity AND INCREASE pressure.

Don't think so? Then why is the twist rate reduced on the higher velocity 6.8 SPC-2 cartridge vs. the original/SAMMI spec. 6.8 SPC?

"...unless you're shooting 123g bullets or smaller..."

You mean LIGHTER, not smaller, standard 6.5mm bullets are .264". At least learn the correct nomenclature.

"...and get a longer barrel."

A longer barrel does NOT always mean higher velocity. Depends on where in the barrel peak pressures are reached. Beyond a certain point a longer barrel can actually decrease velocity!

CV


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## barebackjack

CV-580 said:


> "Most AR platforms have... and utilize a 1-8.5" twist."
> 
> Internet BS.
> 
> "xdeano", do you even own an AR rifle of ANY type?
> 
> Own more than a few, that I actually use and shoot and NOT one has a 1:8.5" twist, regardless of the cartridge or caliber, NOT one.
> 
> Far more common are 1:7, 1:8, 1:9 or 1:12 for the .223R and 1:10 for the AR-10 "types". Even my Satern barreled 6.5 Grendels have a 1:8.75" twist, close to 1:8.5" but still NOT 1:8.5".
> 
> I'll let the wanna-be internet experts proclaim which is most popular, hopefully one of the real experts on here will know.
> 
> "So you wouldn't be able to spin heavier/higher BC bullets as well..."
> 
> How much heavier than 77g and 80g bullets do you want to shoot out of a 16" barrel?
> 
> "...and with the shorter barrel length you won't have the extra 50-100fps or so."
> 
> Your target will NEVER know the difference and if you think 50-100 fps (at the muzzle) is going to matter you are just kidding yourself.
> 
> CV


Pretty sure all of DPMS's .260s and 6.5C's are 1:8.5................................yup, they are.

Kreiger also makes an AR barrel in 1:8.5 twist for the .260.

Just because you don't own a 1:8.5 doesn't mean they aren't out there, and aren't extremely popular for the .260.

Its no big secret 1:8.5 is an EXTREMELY popular twist rate for the .260 Rem. Gives some nice lee way in bullet weights versus 1:8 or 1:9 where you're kind of limited to either "heavy" or "light" bullets respectively.

And if you dont notice a velocity difference of 100 fps, your not shooting far enough. With a .260 Rem shooting 123 gr bullets, 100 fps means 1.5 MOA less drop at 1000 yards and just under one MOA less drift, all else equal. That is pretty damn significant!

As for your brass comment, 6.5C is ten times harder to come by than .260, especially now that Lapua is making brass for it and since Remington pulled their heads out of the dirty dark hole and have realized the .260 is alive and well despite their best efforts to kill it. Remington, Nosler, Norma and Lapua all make .260 brass, who makes 6.5C??? Hornady???

By the way, its a 6.5 Creedmoor, not Creedmore.


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## People

Physical law... It takes MORE energy to spin a bullet faster. With all other factors equal, increasing the twist rate will DECREASE velocity AND INCREASE pressure.

Don't think so? Then why is the twist rate reduced on the higher velocity 6.8 SPC-2 cartridge vs. the original/SAMMI spec. 6.8 SPC?

Not to bash you or anything like that. It does take more energy to spin or move something faster that it was moving before. Rotationl energy is energy. It takes less energy to get a bullet rotating at 1:12 than it does to do 1:8.

Here is a little test you can do. Since it sounds like you have plenty of AR-15's laying around. Do a little load development to make sure it is save in your uppers. Then with the same powder charge shoot a heavy bullet from your 1:7 or 8 twist barrel then from one of your 1:10 to 1:12 tubes. The slower twist rate should be faster. I do not care that the bullet will tumble that will happen after the chronograph any way. This just a speed test.

That test will show you why the twist was stepped back for the 6.8spc. In most cases the really fast twist is not needed.

As we know the need for twist is directly related to the length of the bullet. That is why the M249 and M16A2 have a 1:7 twist tube on it. The tracer for the M856 the L110bullet needs a 1:6 twist for the very coldest temps ammo will fire at. Well how many rounds will be fired at those temps so they figured on it being cold and settled on 1:7. A 62 gr bullet will shoot out of a 1:10 twist bullet as to when it gets very cold I do not know so a 1:9 may not be such a bad idea. Granted most of us stop shooting when it gets cold and we shoot even fewer tracers. Then as to us I would be most of us shoot 55gr bullets most of the time and those can be fired in a 1:12 tube.

Long story short less twist equals faster bullets all things being equal.


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## Plainsman

Some good points. I always find the science behind ballistics interesting. I think you fellows will enjoy this article. It's long, but has some very good information. I didn't understand some of these things until I started shooting copper X bullets, and Lost River Ballistics bullets.

http://anarchangel.blogspot.com/2007/01 ... ology.html


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## Savage260

Do most AR barrels come in 8.5 twist???









Hummmmm.........since DPMS has a good percentage of AR10 type rifles in .260 and 6.5 CM on the market, I would have to say xdeano and others are CORRECT!

As for bullets being Smaller.....









Doesn't take a rocket scientist to figure out the 123gr A-Max is SMALLER than the 140gr SMK, which in turn is SMALLER than the 142 SMK. I am not sure what "nomenclature" you are referring to. Smaller is SMALLER! The 123gr and 140gr bullet are not the exact same size, with one being lighter! One is bigger, and heavier, one is lighter and SMALLER. :thumb:

They both have the same diameter, but not the same SIZE.

Since when do you have to OWN an AR to know a lot about them? I have owned or do own 9 different AR rifles, some I built, some were partial builds, and some were straight factory. Does that mean I know more than a person who only has 2? :shake:


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## Plainsman

I don't know what the point was, but in the article you will notice they talk about densities. For example a 180 gr X bullet is larger than a 180 gr lead bullet, but they both weigh the same. As a matter of fact a 180 gr X bullet is about the same size as a 200 gr lead bullet. Barnes likes to tell you they have a much higher ballistic coefficient and although I like them I don't believe that. 
I'm not sure if any points this simple were made, and I don't want to insult anyone's intelligence, but I think everyone here knows a 200 gr 44 caliber doesn't have the ballistic coefficient of a 200 gr 30 caliber. Actually a 240 gr 44 caliber doesn't have the ballistic coefficient of a 150 gr 30 caliber. 
This may be a helpful subject to some people including me. It got me to google and find that article I posted. I felt better after reading it because it confirmed some things I had thought about, but didn't know if I was right or not. Of course maybe I and that author are both wrong.  
One thing I am sure of, I wish my DPMS was a 1-8 instead of a 1-9 because it shoots a plain Jane 55 softpoint better than the 69 gr SMK.


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## Savage260

Plainsman, I assume you are directing that toward me. CV-580 made a smart a$$ comment about xdeano calling bullets "smaller". So I used the pic to show that even though they can be the same diameter some are really smaller than others.

Read some Bryan Litz if you want to find some good BC info. He is using G7 instead of the G1 model for finding BC and is much better at getting real life values. I am reading one of his books right now and it is an eye opener. He is the head ballistician for Berger. Barnes, and Nosler among others are well known for giving high BCs to their bullets. While the values are true, they are only for the very small envelope of velocity which gives the best value. Their BCs are not BS, but not the whole truth either. I have found my TSX bullets to be only slightly longer than other bullets of the same weight and diameter. Not nearly as bad as some say, but also not nearly as good as Barnes says either!


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## Plainsman

It was to you, but the first part about what was the point I was talking about CV-580. He some points, but fell down on others.

I agree with you on the X bullets. I didn't measure, but when X bullets first came out I remember setting a 180 next to a 200 gr Partition and they appeared to be the same length. At first I thought they would have a higher ballistic coefficient, but on second thought it's a little like throwing a wiffle ball and a real ball. Not that bad, but I'm just pointing out that density enters the picture, but then reading your post you already know that. Like I said in the previous post, I don't want to insult anyone's intelligence, it's just interesting.
I notice when you use the ballistic calculator on the Berger Bullets site they let you choose the G7 or G1 ballistic coefficient. I have never used the G7. My old chronograph was crapping on me so I bought a new one. I got brave when the new one came and started digging into the old one and found a broken wire. Now I have two. I think I will set them in line so I can calculate my own ballistic coefficient. Things have to be different coming out of different rifles. Some will deform the bullet more than others etc. My old chrony program would calculate ballistic coefficient from two readings. Now I need to see if I can find a formula through google or somewhere.


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## xdeano

Plainsman,

you can give this a try. Just plug in your velocities at your 10ft and your 100yd chronographs, and you will be pretty close. I've always planed on doing this, I've just been lacking a second chrono. Should be pretty easy to set up. This will give you your G1/G7 to plug into which ever program you wish.

http://www.jbmballistics.com/cgi-bin/jbmbcv-5.1.cgi

xdeano


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## Plainsman

Hey thanks xdeano, I appreciate the help. I had not even started looking yet. My old Chrony program used ???? oh, heck I can't remember the terminology, but you had to type in C:ballistics to get into the program. I'm to cheap to buy the same program over again simply because it's outdated. Especially when you own their chronographs and programs and they don't give a break on the update.


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## xdeano

Plainsman, 
LOL, if you had to use a prompt, then you're way better off with the free stuff online.  I know we messed with some Sierra stuff a while back. I can't remember if that has it on there or not. I know that Pejsa program for Palm has it. But with the more recent programs such as "Shooter" you'll be give their G7's and such right out of their library, not sure if you've gone that direction. The JBM free stuff is just as good. Give it a shot. No sense in giving your money away when you can get it free, right? 

Deano


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## AdamFisk

I'm still in the process of shooting and recording drops, as well as working on my damn note taking, as I am horrible at writing important crap down and keeping records, BUT, I do know that with my Shooter program and the 155 Scenar, in my rifle, the "regular" BC ballistics are more accurate than Litz's G7 BC. Again, I'd have to do some serious digging to find exactly what the results were, but a few different times now I've shot at various distances using the drop from one, and than the other, and when using the G7 BC, it wasn't as accurate as the G1. The G7 usually put me high.


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## xdeano

right, but with the published G1/7 it is at their location. If you were to use 2 chronographs at your location to record velocity and temp, pressure, density altitude... you'll find that your G1/7 will be slightly different than the published, and be more accurate for your particular weapon to boot. This is what Plainsman is looking at.

xdeano


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## Savage260

That makes no sense to me that the G1 would be closer than the G7 model. The drag models are very different, so unless your velocity or altitude ect, is way off what they did it should be much closer with a LR style bullet. I know mine with the shooter program has been dead on for the bullets I have used. Using the Hornady 105 Amax I hit the 878 yd steel on the second shot in a swirling wind. The number of clicks it gave was dead on, just took some wind reading. Has been very good with the Sierra 175smk and my 308 also.

Adam, are you sure your chrono is correct? And are you using the gps to input your temp, pressure, alt and such? The program automatically compensates for any differences between your current info and the info used at the time the G7 was calculated, so unless the conditions are off, the velocity would have to be off. Or the program is bad.


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## AdamFisk

No, my velocity is pretty spot on I believe. It was averaged out with 2 different chrono's, both coming up with the same thing.

And I have the Bluetooth Kestrel that automatically uploads all the weather data right to Shooter, so that shouldn't be the problem either.

I just looked on my phone, for 1000yds the G7 gives me 1.8MOA drop above the G1 model. That's pretty dang significant. Maybe I need to look into this thing Deano and Plainsman were talking about, figuring out a guy's own BCs.

From this point forward, I'm going to start recording what the G1 gives me, what the G7 gives me, and what was actually needed, in an organized fashion. I tried finding the notes I had from them 1 or 2 days where I noticed and recorded the differences between the two, but they are lost.


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## xdeano

i'm not arguing that the G1 is better, because i know that the G7 drag pattern is much better for our bullets today, vs the mini balls that were shot years ago.

I'm just agreeing that you'll find a different G1/7 at your current location than with published data. It won't be much though.

I can confirm that 878yd hit, and it was a bit of a wicked wind. swinging in from the left and up and over that hill, made things interesting.

I know were getting kind of off topic on this thread, but it's good discussion anyhow for those who care.

xdeano


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## Savage260

After reading "Applied Ballistics for Long Range Shooting" it doesn't surprise me at all that your data shows a 1.8 MOA differance at 1000yds. That is because the G1 model has a much higher drag which would make the bullet drop a lot more. I hope to get a lot more shooting in this fall using my chrono, shooter program and various distances. It will be interesting to see how every thing shakes out!


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## barebackjack

Im surprised nobody has brought this up, but there is a pretty simple method of figuring out what your REAL WORLD BC's and external ballistics are.

All you have to do is go shoot your rifle.

Maintain your zero and shoot a 500 yard group not correcting for drop. Measure your drop and its a relatively easy task of reverse engineering your ballistics table off that. You can determine your real world BC (not what some manufacturer trying to sell you a product tells you) and can than apply this to all other ranges. Its a pretty low tech means of achieving a higher degree of accuracy, all you need is a big cardboard box like a refrigerator box, and a calculator.

Do this a couple times to check precision, you can even do this at subsequent farther distances and be even more precise in your calculations if you have a big enough target.

Published ballistics calculators are great, and usually pretty darn close (as are most published BCs), but ive found that none of them are 100% accurate, so ALL my rifles get a real world confirmation as to what they are actually doing.


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## Plainsman

BBJ, I did that back in 1954, on the side of the barn, with my first BB gun, but everyone tells me this new fangled deal is only good for 800 rounds so I don't want to burn it up doing that. Besides how big of a fridge box do I need to calculate my 1500 yard drop? I'm not trying to be disrespectful, I'm just in a humorous way to say I don't think it's practical for me. Maybe I'm wrong though because I will often shoot at 800 yards and take note of my bullet strike high or low. I then mess with my program until it agrees. Most time all other ranges then fall into line too. 
BBJ, your absolutely right, and I would use that method out to about 800 yards with a 308, 243, etc. These darn barrels cost to much to use that method. I have burned through 200 rounds already and am starting to worry I will need a second barrel after I have everything the way I want it, and that is for only the 140 Berger VLD. I would like to also have a load using the 120 Ballistic Tip. Maybe I should start saving for that new barrel now.


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## Savage260

BBJ, have you checked your real world info against a ballistics program to see how close(or not) they really are? I guess I am of the mind that if a program can get me within a click or two at 1000yds that is pretty darn good. I can't shoot that well any way, and certainly wouldn't be shooting at an animal at that range. I just find it hard to believe the published G7 numbers can be off. With all the time and money they put into calculating these things, and the brilliant people doing the work, I just can't see them being off much at all. The pesja program had me within a foot or so, depending on wind at 910yds, and the Shooter program got me within inches with a crazy wind at 878, so I think the stuff has to be dang close.


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## barebackjack

Plainsman said:


> BBJ, I did that back in 1954, on the side of the barn, with my first BB gun, but everyone tells me this new fangled deal is only good for 800 rounds so I don't want to burn it up doing that. Besides how big of a fridge box do I need to calculate my 1500 yard drop? I'm not trying to be disrespectful, I'm just in a humorous way to say I don't think it's practical for me. Maybe I'm wrong though because I will often shoot at 800 yards and take note of my bullet strike high or low. I then mess with my program until it agrees. Most time all other ranges then fall into line too.
> BBJ, your absolutely right, and I would use that method out to about 800 yards with a 308, 243, etc. These darn barrels cost to much to use that method. I have burned through 200 rounds already and am starting to worry I will need a second barrel after I have everything the way I want it, and that is for only the 140 Berger VLD. I would like to also have a load using the 120 Ballistic Tip. Maybe I should start saving for that new barrel now.


You dont need to actually calculate your 1500 yard drop. If you calculate one known distance drop, and know your MV, you can than calculate all the other stuff for ANY distance. Best part is, you can calculate your actual BC, plug that into a ballistics calculator and become more accurate off that.

It doesnt cost you any more rounds than shooting through a chrony at 100 yards.

And if your worried about burning your barrel up, well, thats what you get for buying a barrel burner. :wink:

Im just saying, this is just another way to determine ones actual BC. Not everyone has a chrony, let alone two. I for one would be pretty picky about who I let sling lead over my chrony at 100 yards as well. Ive seen first hand, they dont handle lead to well. :lol:

One could take their MV readings, than move the chrony out to 100 yards, but I think for absolute accuracy they have to be taken simultaneously off the same round? I could be wrong there. More than one way to skin a cat.


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## barebackjack

Savage260 said:


> BBJ, have you checked your real world info against a ballistics program to see how close(or not) they really are? I guess I am of the mind that if a program can get me within a click or two at 1000yds that is pretty darn good. I can't shoot that well any way, and certainly wouldn't be shooting at an animal at that range. I just find it hard to believe the published G7 numbers can be off. With all the time and money they put into calculating these things, and the brilliant people doing the work, I just can't see them being off much at all. The pesja program had me within a foot or so, depending on wind at 910yds, and the Shooter program got me within inches with a crazy wind at 878, so I think the stuff has to be dang close.


Ive put the real world data for my specific loads up against several ballistics calculators. And your right, they are often very close. Close enough to where 99.9% of guys wont notice, wont care, and cant shoot the difference anyway.

However, my .22-250 load for example, when plugged into several calculators was consistently off about 2-3" at 400 yards compared to what it did in real life. Doing the math, I was getting a different BC in real life versus what the manufacturer was advertising. Is roughly 1/2-3/4 MOA at 400 a big deal? On a rifle that shoots slightly better than that, to me, it is.

On the flip side, my .308 load was under .25 MOA, which is less than I could adjust for via turrents. So definitely a moot point.

The difference, I think, was in the .22-250 I shoot Noslers, in the .308 Lapua. Ones a premium bullet, the other is a more "run of the mill" bullet. It showed when checking the math. Noslers advertised BC was off, Lapuas was extremely close.

The thing you have to remember about advertised BC's (especially since everyone is now a weekend sniper and everyone and their mother is into long range shooting now) is that the manufacturer WANTS you to buy their bullets, and with more people understanding applied ballistics and more people getting into the long range game, high BC is a selling point (whether its actually there or not). Morale of the story, take advertised BC's with a grain of salt.

Many of the premium bullets like Berger and Lapua are very very close in their advertised BC's. Others are pretty liberal in them.

I highly recommend to any anal retentive long range shooter to take the time and calculate THEIR BC, you may find it to be a waste of time, you may not, but at least than you'll know beyond a doubt.


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## Savage260

BBJ, that is kind of what I was expecting to hear. Nosler's published G1 BC is the number for the very top velocity band so it is quite misleading. At least Sierra gives BC for 3-4 velocity bands so you can adjust for your usage. Hard to do if a person thinks .450(or what ever they may give) is the BC no matter what the velocity.

I am one of those guys that can't shoot the difference, so I am happy with hitting the 12"X12" steel at 878.


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## Plainsman

BBJ, gotcha. Ya, that's sort of what I had to do with my 308 with SMK. I was off like your 22-250 was off. Since it was not a real long range rifle I sighted at 100 yards then shot at 600 yards. Playing with the program until it added 1.5 minutes of angle at 600 yards. After that it was good to 1000 and it really wasn't worth trying for more range out of my 308. 
I first noticed the problem when I was dropping much lower than I should have on 800 yard targets. I think I posted about that problem.


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## CV-580

Let's try this again for those of you who do NOT read or comprehend what is written...

What "xdeano" said was "Most AR platforms have relatively short barrels and utilize a 1-8.5" twist."

The words he used are "Most AR platforms..." and ..."utilize a 8.5" twist".

Neither him or I mentioned SPECIFIC brands or SPECIFIC calibers/cartridges.

"Pretty sure all of DPMS's .260s and 6.5C's are 1:8.5...yup, they are."

DUH! AGAIN, we are talking "Most AR platforms..." and NOT just the .260R and 6.5C CARTRIDGES.

"Kreiger also makes an AR barrel in 1:8.5 twist for the .260."

Once again, we are talking "Most AR platforms..."

"Just because you don't own a 1:8.5 doesn't mean they aren't out there, and aren't extremely popular for the .260."

Never said "since I don't have an AR in 1:8.5 they don't exist. What I disagreed with was that "Most AR platforms... utilize a 8.5" twist".

Get it yet, I was talking about "Most AR platforms utilizing a 8.5" twist" and NOT the .260R.

"Its no big secret 1:8.5 is an EXTREMELY popular twist rate for the .260 Rem. Gives some nice lee way in bullet weights versus 1:8 or 1:9 where you're kind of limited to either "heavy" or "light" bullets respectively."

Really does NOT matter, if you READ THE WORDS written, I disagree with the statement "Most AR platforms... utilize a 8.5" twist".

"Hummmmm... since DPMS has a good percentage of AR10 type rifles in .260 and 6.5 CM on the market, I would have to say xdeano and others are CORRECT!"

Well at least you said "AR-10 TYPE rifles" since DPMS does NOT make any AR-10 rifles. ONLY ArmaLite makes an AR-10.

One last time, it really does NOT matter if DPMS makes 1% or 100% of "AR10 type rifles in .260 and 6.5 CM on the market". The statement "xdeano" said that I disagreed with was that "Most AR platforms... utilize a 8.5" twist".

Can you comprehend now?


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## knutson24

I have been following this thread for a while and could care 6 one way or half a dozen the other but being the original topic was about the 6.5CM and .260 Rem I automatically assumed Xdeanos comment was in reference to those two cartidge chamberings. Which was aslo what the others following this thread assumed I imagine hence all of the other backlash you received for calling the BS flag on him.

"The key to conversation at work is flexibility and understanding how what you say might be perceived by others."- Deborah Tannen

v/r

Knutson


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## xdeano

CV-580,

Really?!? You need to get up to speed. Go back to the top of this thread, it will read;

"6.5 credmore versus .260 rem on ar"

These are both 6.5mm rounds. Why would I talk about a .223 when the topic of discussion is 6.5mm rounds? Maybe I should have clarified that I was talking about a 6.5mm round, oh wait, what was the topic of discussion again?

DPMS Arms Inc utilize a 1-8.5" twist:
http://www.dpmsinc.com/store/products/?prod=2003
http://www.dpmsinc.com/store/products/?prod=5294

Just for starters... And thank you for taking this thread in the wrong direction.

xdeano


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## Savage260

Well, DUH, to you too. Looks like only one person here has a problem with comprehension. The rest of us knew the thread was about the 6.5s, why didn't you? Looks like we will have to type slowly and use small words to make sure every one understands precisely what is said how it is meant to be taken and in what context. Most 30-06 I have seen use a 1-10"twist, but my 6-06 sure doesn't.............DUH!


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## Plainsman

> "Most AR platforms have... and utilize a 1-8.5" twist."
> 
> Internet BS.
> 
> "xdeano", do you even own an AR rifle of ANY type?
> 
> Own more than a few, that I actually use and shoot and NOT one has a 1:8.5" twist, regardless of the cartridge or caliber, NOT one.


CV-580 I got off subject like you because I found this article very interesting and wanted to join in on the conversation. However, I hope I don't come off smart a$$ like you did. After shooting for 50 some years I sometimes get good pointers on here from people with much less experience, but fresh enthusiasm. As a matter of fact one fellow who kept PMing me for information dropped a bit of information for me one day and he didn't even know it. I have also been reloading for more than 50 years and this guy mentioned he was running out of sizing wax. I had never used the wax and asked him about it. Boy had I been missing the boat.

Also, I am an old bolt action guy and new to the AR. Lets not stifle the conversation with a race to see who is the brightest or most experienced or the gun guru. I always consider anyone who launches an arrow or throws lead downrange a brother. Keep the hard debate for politics and hot topics. In these threads we are all here for information and the company of like people.


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## CV-580

"These are both 6.5mm rounds. Why would I talk about a .223 when the topic of discussion is 6.5mm rounds?"

VERY SIMPLE, because YOU said "Most AR platforms...".

YOU went on a tangent and expanded your comments to include "AR platforms".

"Maybe I should have clarified that I was talking about a 6.5mm round..."

Yes, if you had said "Most 6.5mm AR platforms..." I would have agreed, 1:8.5 is close enough and maybe even correct.

"...oh wait, what was the topic of discussion again?"

You are still confused? :lol:

Yes, it was .260R/6.5C but then YOU added "Most AR platforms..."


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## Plainsman

I would like to see this discussion get back to 6.5 Creedmore vs 260 Remington on AR. Enough of who is right and who is wrong, and who said what. Anyone want to lead off? I'll give it a shot although because of my experience I may be off subject.

The only 6.5 I have is a 6.5 X 284. The only AR I have is a 223. They both have a 1/9 twist, and I wish both were a little faster twist. My cooper is shooting good though and I suspect that the 140 Berger VLD is stabilizing because of the slightly higher velocity which is near 3000 fps. What do you guys think?
I should go back and read what everyone has said, but I'm working hard for an old geezer today and I'm to lazy to go look back. So my question is the Creedmore has a slightly longer neck, but the same case capacity. Close anyway. I would guess the longer neck is perhaps better for a number of reasons. First would be the ability to shoot the longer bullets without getting into the case capacity, and second I remember Xdeano talking about longer necks perhaps moving the heat further forward and extending throat life. Again, what do you guys think.

I had another question, but I think I better start a new topic for it.


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## xdeano

Well we've kind of settled that the two cartridges in question are running about a horse a piece. The one thing that I'd like to see for the AR manufactures would be a faster twist rifling like a 1-8" twist. I've got a couple of friends that are running the 6.5 Creedmoor as their primary coyote/target rifle. He's got 12"x 12" AR500 plates out to 900yds off the back deck and the Creedmoor is more than capable of reaching out with accuracy. I think the 260 might be more suited for the bolt gun, and the Creedmoor be more suitable for the AR just due to case length.

To comment on the long necks Plainsman, I'm actually planning on going forward with a 6mm Super LR, the one with the longer necks that run a 105-108g bullet at 3150 to 3200fps. With low SD, ES. So i'll let you know when i finally get everything rolling. Neck length is .3207 with a 30 degree shoulder. They also make a 6.5mm SLR which is made for the AR platform.

6.5 Creedmoor has a 30 degree shoulder, .2853" neck length
260 Remington has a 20 degree shoulder, .2594" neck length

an efficient funnel has a 30 degree angle so if it were me I'd pic the creedmoor for shoulder angle. Shoulder angle makes a difference in efficiency. I'm not down grading the 260 because I've shot several of them over the years and they do the job.

With neck length the Creedmoor also gets my nod. The longer the neck is (to a point) the more you can mess with seating dept without really compromising powder capacity. The ideal placement of a bullet is right at the shoulder/neck junction, and not below. But with most factory guns with mag length being the issue bullets are set below that magic line.

Now as far as brass... the 260 has some new stuff on the market, Lapua has stepped up. This is great for reloaders who what to get that little bit more out of their reloads. In an AR platform I wouldn't be using it, because i'm not one for a brass catcher and I do most of my shooting in the field. For the AR i'd fall back on the Remington brass, it's easier to loose without crying. For the Creedmoor brass was an issue to get here just a few months ago, but it's been getting a little easier to get your hands on, down fall is that Hornady is the only manufacture that is making brass at the current time that I know of.

Another thing that you may encounter with an AR platform is the brass hitting the forward assist ramp and brass stretch.

I'm sure i could find some more pros and cons... They're both a great choice for an accurate long range rig.

xdeano


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## barebackjack

CV-580 said:


> "These are both 6.5mm rounds. Why would I talk about a .223 when the topic of discussion is 6.5mm rounds?"
> 
> VERY SIMPLE, because YOU said "Most AR platforms...".
> 
> YOU went on a tangent and expanded your comments to include "AR platforms".
> 
> "Maybe I should have clarified that I was talking about a 6.5mm round..."
> 
> Yes, if you had said "Most 6.5mm AR platforms..." I would have agreed, 1:8.5 is close enough and maybe even correct.
> 
> "...oh wait, what was the topic of discussion again?"
> 
> You are still confused? :lol:
> 
> Yes, it was .260R/6.5C but then YOU added "Most AR platforms..."


Its ok bud, we forgive you for not reading the thread title.

Everyone thats contributed to this thread except you understood what xdeano said with "most AR platforms". Dont worry though, ill call him and tell him to slow down and type v e r y s l o w l y for you next time.


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## barebackjack

xdeano said:


> Well we've kind of settled that the two cartridges in question are running about a horse a piece. The one thing that I'd like to see for the AR manufactures would be a faster twist rifling like a 1-8" twist. I've got a couple of friends that are running the 6.5 Creedmoor as their primary coyote/target rifle. He's got 12"x 12" AR500 plates out to 900yds off the back deck and the Creedmoor is more than capable of reaching out with accuracy. I think the 260 might be more suited for the bolt gun, and the Creedmoor be more suitable for the AR just due to case length.
> 
> To comment on the long necks Plainsman, I'm actually planning on going forward with a 6mm Super LR, the one with the longer necks that run a 105-108g bullet at 3150 to 3200fps. With low SD, ES. So i'll let you know when i finally get everything rolling. Neck length is .3207 with a 30 degree shoulder. They also make a 6.5mm SLR which is made for the AR platform.
> 
> 6.5 Creedmoor has a 30 degree shoulder, .2853" neck length
> 260 Remington has a 20 degree shoulder, .2594" neck length
> 
> an efficient funnel has a 30 degree angle so if it were me I'd pic the creedmoor for shoulder angle. Shoulder angle makes a difference in efficiency. I'm not down grading the 260 because I've shot several of them over the years and they do the job.
> 
> With neck length the Creedmoor also gets my nod. The longer the neck is (to a point) the more you can mess with seating dept without really compromising powder capacity. The ideal placement of a bullet is right at the shoulder/neck junction, and not below. But with most factory guns with mag length being the issue bullets are set below that magic line.
> 
> Now as far as brass... the 260 has some new stuff on the market, Lapua has stepped up. This is great for reloaders who what to get that little bit more out of their reloads. In an AR platform I wouldn't be using it, because i'm not one for a brass catcher and I do most of my shooting in the field. For the AR i'd fall back on the Remington brass, it's easier to loose without crying. For the Creedmoor brass was an issue to get here just a few months ago, but it's been getting a little easier to get your hands on, down fall is that Hornady is the only manufacture that is making brass at the current time that I know of.
> 
> Another thing that you may encounter with an AR platform is the brass hitting the forward assist ramp and brass stretch.
> 
> I'm sure i could find some more pros and cons... They're both a great choice for an accurate long range rig.
> 
> xdeano


Ohhhhh ohhh ohhhh, can I add one more con???????!!!!!!............reliability, shhhhh.

Ooooo I bet the AR crowd jumps on me now!


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## hagfan72

barebackjack said:


> Ohhhhh ohhh ohhhh, can I add one more con???????!!!!!!............reliability, shhhhh.
> 
> Ooooo I bet the AR crowd jumps on me now!


 :rollin: :beer:


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## knutson24

Why would an AR be any less reliable than any other "properly maintained" semi auto?

I have ran probably close to 2,000 rounds through one of mine and have never had any malfunctions.
Now if you had said dirty I would have totally agreeded.


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## Savage260

BBJ, do you even own an AR or know any thing about them? :wink:

My piston driven AR is so much more reliable than any other AR I have ever owned it is like a bolt gun. I have thousands of rounds through it and it never malfunctions! Oh, wait, were you talking about just the old style or all ARs? You didn't specify so I can't be sure what you are talking about! oke:


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## TN6.5-260

first post here and maybe I'm a little slow but when I read "Most AR platforms have relatively short barrels and utilize a 1-8.5" twist." and I also thought he was not talking about "6.5 ar rifles" but exactly what he said, "most ar rifles" which is all calibers and not just 6.5mm.
pointing out that this is not true of "Most AR platforms" as written is important since some of us are not experts and need correct information.

TN


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## Savage260

Great, now there are two of you, at least CV580 isn't alone any more. Would have been a simple misunderstanding until CV got sand in his kitty over xdeano's post and acted like vinegar and water.

My wife(who doesn't know what an AR is) even understood what the thread was about when she read it......COME ON MAN!!!


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## TN6.5-260

"Great, now there are two of you, at least CV580 isn't alone any more. Would have been a simple misunderstanding until CV got sand in his kitty over xdeano's post and acted like vinegar and water."

sorry to offend an internet expert on my first post!


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## AdamFisk

:dead:


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## xdeano

Well I'm not going to go back and ammend any of my previous posts just so some of the more challenged readers can figure things out. Go the the beginning of the post and get caught up, don't just jump in at the end and think you'll get any simpathy from me, follow along. I'd start with the topic of the post and keep that in mind. :thumb: Apply that topic to the following posts as implied.

xdeano


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## Plainsman

TN6.5-260 I admire your sympathy for others. If you follow this thread from the beginning you may notice I tried to give him some credit for his ideas.


> It was to you, but the first part about what was the point I was talking about CV-580. He some points, but fell down on others.


The biggest fall CV580 took was his impolite manner. You may have also noticed I also said:


> I would like to see this discussion get back to 6.5 Creedmore vs 260 Remington on AR. Enough of who is right and who is wrong, and who said what. Anyone want to lead off? I'll give it a shot although because of my experience I may be off subject.


I got into this thread for two reasons. First because since I recently purchased a 6.5 I am interested in all 6.5's. Actually I have been for years, but just bought one now. The other reason was to get back on track. The problem isn't what CV580 said, but he ruffled feathers the way he said it. People in politics and hot topics argue all the time, but people on these threads are here to share experience and learn. This isn't called the smart *** thread. That's what CV580 didn't understand.

OK, back to the real subject please.


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## xdeano

Thank you for the course correction.

xdeano


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## barebackjack

Heh heh heh.


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## TN6.5-260

funny, I thought this was going to be a good forum!

a person doesn't understand what "everyone" supposedly should understand and certain people keep attacking him and now me maybe more than 2 of us don't understand that "Most AR platforms" only means 6.5mm ar rifles

plainsman askes to get back on subject and cv580 doesn't continue with his valid point but several internet babies have to keep making off subject negative comments and continue their childish & a$$inine attackes

tn


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## barebackjack

Heh heh heh heh. :rollin:


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## Savage260

Another great post TN. :eyeroll: This forum is very good, but whiney posts like yours don't help things. Suck it up, be a man, and get on with it. If you don't understand some thing read up and get on with it. Just because we understand doesn't make us "experts" and because we don't stand for others making jacka$$ posts when they don't understand doesn't make us "babies". If that is all you can add to this site, please, by all means, don't come back.


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## Plainsman

TN, I make a lot of mistakes. I would guess we all do. I'm not ticked, or anything like that, but since this is an interesting thead I want it to get back on subject. Things like this are to good to loose with bickering.

A year ago I would have gone with the 260 hands down, but there are many things about that creedmore that are really attractive. First is the long neck, shoulder set back, and the ability to shoot the long skinny bullets. It sure as heck would be easier on the barrel than my 6.5X284. However, I am having fun buying 284 Winchester brass, sizing, and turning the necks to .014.


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## MikeyLikesIt

Would that be Convair 580?


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## KurtR

i guess in my simple mind i thought we were talking about the 6.5 cal platform. So with a liitle comprehension i deduced that when they said" bbl twists are usally 1-8.5" in most ars" it was in the 6.5. Well because the big bold title letters when this first started says so. Well any way attention to detail who needs it.


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