# What the Heck? COAL Variances



## AdamFisk (Jan 30, 2005)

I was very aggravated tonight. I started loading up some 155 Scenars after trickle charging every charge the best I could; I was trying to be "extra" anal and consistent tonight. Anyways, got the die set and seated 3 or 4 bullets to my objective of 2.800". Than the next few started varying. I didn't change a thing, tried to keep the pressure and speed when seating the bullets consistent. I pull out the comparator and measure the "off" ones against the good ones. Measuring tip to tip I had a variance between 2 cartridges of 6 thou, measuring with the comparator the variance was 1 thou....So I said screw it, after wasting all my patience on dropping powder, and reloaded the rest of my 40 rounds without measuring them, as it would just piss me off.

Out of curiosity, I went back and measured every cartridge tip to tip with caliper, and than took ogive measurements with the comparator....40 cartridges.

Caliper:
2.793" - 2.5%
2.795" - 7.5%
2.796" - 7.5%
2.797" - 5%
2.798" - 20%
2.799" - 7.5%
2.800" - 30%
2.801" - 10%
2.802" - 10%

Comparator:
2.159" - 5%
2.160" - 20%
2.161" - 30%
2.162" - 37.5%
2.163" - 7.5%

So, question 1 is, are these variances acceptable for shooting out to 500yds or so?

Question 2, how in the hell do I improve my consistency when seating bullets. I've been struggling with this since I started reloading about a year ago. Maybe I just can't operate a damn caliper. Seems everybody else I talk to does not have these kind of variances when measuring COAL with a caliper. Maybe it's not as bad as I think, since the comparator measurements come out pretty dang good, I don't know. I am using a plain jane RCBS seater die.

I would think match grade Lapua bullets would be more consistent than that.


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## Plainsman (Jul 30, 2003)

The hollow point match bullets often have an inconsistent metaplate. Match shooters will buy a tool to cut their metaplate to uniform profile. Look at the tip and you will see that many have lower edges on one side higher in spots etc. The weight will be consistent, but the metaplate often is not. You will find inconsistency in lead tip bullets also. Full metal jacket and polymer tip are very consistent.


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## AdamFisk (Jan 30, 2005)

So the results with the caliper are normal you're saying, for this type of bullet?

What about the comparator measurements? 88% of the cartridges measured within 3 thousandths of each other. Obviously that is my inconsistency in seating the bullet, isn't it? Is that little bit of a variance cause for concern?


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## Plainsman (Jul 30, 2003)

The comparator is going to be more accurate than measuring of the metaplate. I don't worry about a couple of .001


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## KurtR (May 3, 2008)

Were you measureing from the tip or from the ogive of the bullet as the ogive is more accurate reading the metaplate can varry and is inconsistant. Why are you loading them so short from what i have sceen with the scenars they like to jump less than more and push thos sexy little pills as hard as is safe to get the most out of them.


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## xdeano (Jan 14, 2005)

like plainsman said the hollowpoints, even though they're Lapua will have inconsistencies. measure from the Ogive back instead, it'll give you much more reasonable answers. So pick up a comparator and run, because you just found another clue to the consistency variable. 

xdeano


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## xdeano (Jan 14, 2005)

Dangit KurtR you stole my thunder...
xdeano


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## AdamFisk (Jan 30, 2005)

KurtR said:


> Were you measureing from the tip or from the ogive of the bullet as the ogive is more accurate reading the metaplate can varry and is inconsistant. Why are you loading them so short from what i have sceen with the scenars they like to jump less than more and push thos sexy little pills as hard as is safe to get the most out of them.


I bought this.rifle from a buddy who had done the majority of load testing before he decided it wasn't good enough, my gain. :lol: He tested loads from the book 2.80 all the way up to damn near touching the lands. All testing was done at 300, and the loads that shot the best were, strangely, the shortest and longest ones. The short one grouped on average .60" for 3 or 4 groups. The long load, for an average of 5 groups, shot an inch and a quarter I think. I'm not near the shooter he is, but I loaded up some of the short loads to see wjat I can do with them, and also chrono them, as I don't think he did that. I'm afraid they'll be awful slow being pushed by only 46gr varget, but if they shoot that well I can live with it I think.


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## AdamFisk (Jan 30, 2005)

Also, the same 2.80 load shot .5 moa out of my Finnlight at 200...so it shoots well in both guns, which is a plus.


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## barebackjack (Sep 5, 2006)

AdamFisk said:


> I'm afraid they'll be awful slow being pushed by only 46gr varget, but if they shoot that well I can live with it I think.


Im pretty sure they were right around 2850.


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## barebackjack (Sep 5, 2006)

And the offer to buy that rifle back still stands.


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## AdamFisk (Jan 30, 2005)

barebackjack said:


> AdamFisk said:
> 
> 
> > I'm afraid they'll be awful slow being pushed by only 46gr varget, but if they shoot that well I can live with it I think.
> ...


Close.

2860fps avg, 10 shot string, 12 degrees F outside.

And that load don't do too shabby at 100 and 200 either.....But it doesn't take long for that windchill to start affecting groups. How nice it would be to have an indoor shooting house.


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