# True boattail at hypersonic speed from a standard break-barr



## rogervan (Oct 23, 2009)

Hello All,

I don't know how to utilize all the functionalities of this kind of forum, so please forgive me if my post looks primitive.

I'm brand new here. My topic is hypersonic pellet design. I never did write down what the small-waisted, standard pellet design is called. But we know it craps out at hypersonic speed. The manufacturers are making faster and faster rifles, because the public has a romance with them. AFIK, the best high end speed for these pellets is around 850 - 900 ft/sec. From my reading, and from observing what bullet design the ammo makers use on their high-velocity rounds for real, big-game rifles, all seem to go to the Boattail. Boat-tail designed slugs do very well at the highest speeds, like 3,000/ft/sec.

I'm showing a lawyer all the information and hypersonic air rifles for sale, to see if we can get our money back on hypersonic pellet rifles that the manufacturers knew all along would not perform under this disability. I myself shopped for speed when I got my first, super-cool (I like it a lot) adult airgun that shoots lead pellets at 1250 ft/sec.

How I can make a boattail work in an airgun is proprietary, and probably impossible to guess. I've been trying several things in the last five years. I have protected the pellet design through a lawyer who practices close to me.

What would you guys say if I manufactured true boat-tail air rifle pellets? Would you try some out if I sent free samples?

I'm kind of expecting to get razzed out of a conversation, or to be removed by a moderator. They were going to immolate Galileo when he published how he discovered that the earth moves around the sun, instead of the sun revolving around the earth as everyone believed.

Roger


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## blowgunner62 (Nov 23, 2008)

I would definately be willing to try your design. The concept sounds good, but there might get to be a weight issue. But I'm sure that you already thought of that. Interesting idea that might be a major breakthrough if everything is designed right.


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## rogervan (Oct 23, 2009)

Yes I'm aware of the weight issue. Too heavy and it damages the gun.

Roger


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## Ambush Hunter (Jun 29, 2009)

Forget pellets. You will need extra weight of a solid lead bullet, the type big bore airgunners shoot. But then, the most powerful of them are around 600 foot-pounds and NONE of them shoot above the speed of sound. You just can't cheat the laws of physics with guns powered by AIR! Good luck with a project, but I won't waste my time on this...In reality, there is NO need for an airgun to mimic a powderburner.


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## spentwings (Apr 25, 2007)

> I'm showing a lawyer all the information and hypersonic air rifles for sale, to see if we can get our money back on hypersonic pellet rifles that the manufacturers knew all along would not perform under this disability. I myself shopped for speed when I got my first, super-cool (I like it a lot) adult airgun that shoots lead pellets at 1250 ft/sec.


As for class-action lawsuits, their main function is to put money in a lawyer's pocket and maybe, just maybe, prevent similar wrongs in the future.
As for getting any money back to make it worthwhile, I wouldn't hold my breath.


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## darkgael (Feb 10, 2006)

I'm not at all sure about the terminology being used here. Do you mean hypersonic or do you mean supersonic? 
The standard that I am used to for hypersonic is a minimum of five times the speed of sound. Since most airgunning is done close to sea level, that would make hypersonic velocities in the vicinity of 5500fps.
Supersonic velocities we already have. What does your pellet offer that is better? How much of an increase in velocity could one expect to see? How does accuracy stack up? Or.....are you trying to find out these things? (a perfectly legitimate goal)
About hypersonic rifles air rifles currently for sale - reffing the definition above - there are none. That 1250 fps that you got is still pretty much state of the art, just a bit supersonic (speed of sound = 1125 fps at MSL and 20degC.).

" Boat-tail designed slugs do very well at the highest speeds, like 3,000/ft/sec."

Boat tailed bullets are effective because they remain stable as they make the transition from subsonic to supersonic and back again. (one of the reasons that the X-1 research airplane was given the shape of a boattailed .50 cal bullet.) 
There is considerable discussion about this idea in some circles as to how, if at all, it affects accuracy. For instance, many benchrest shooters use flat based bullets and they are shooting one hole groups at 200 yards. 
Pete


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## rogervan (Oct 23, 2009)

I've done a lot of research leading up to this seeming need to improve the air rifle pellet shape. I've read many testimonials that the high-speed pellets are OK at about thirty feet, but farther out, the deflections caused by a period of supersonic flight cause the group to become unacceptably erratic.

I'm very interested in seeing testimonials that refute the notion that this problem exists. Could you put me in touch with anyone, or a group, who understands how pellet-shaped pellets overcome the problem of uneven drag while they are at supersonic speed? Maybe the one-hole groups that you describe are one hole with the first shot, followed by pellets whose deviation takes them far away center to miss the entire target structure. That's just a snort, I believe you about the bench-rest shooters. I hope you can give me some information.

Roger


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## darkgael (Feb 10, 2006)

Roger: With all due respect there is no "need" to improve air gun pellets. There is a desire to do so but not a real need. 
The only test targets that I have seen that were one hole groups were fired at about 460 fps from very expensive match air pistols.
As to discussions about FB vs BT in benchrest shooting, see this link and ask your questions: http://benchrest.com/forums/.
So.....you did mean supersonic??
Pete


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## rogervan (Oct 23, 2009)

Oh yes. I'll probably have to do elaborate experiments to find out if my hunch is correct. I did mean supersonic, and mot hypersonic.

I really do appreciate your reply, and it makes me more intrigued, because it directly says the hour-glass shape pellet is not a good performer in anything but super-duper exotic match pistols.

Roger


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## darkgael (Feb 10, 2006)

Roger:


> it directly says the hour-glass shape pellet is not a good performer in anything but super-duper exotic match pistols.


Be careful there. That conclusion is a bit of a jump. What I said (wrote) was that those were the only ones I'd ever *seen*. BTW - when I write one hole, I don't mean one ragged hole, I mean round one hole only slightly larger in diameter than the pellet.
Top shelf match pistols and rifles come with test targets as a matter of course. That doesn't preclude that other rifles/pistols from being accurate. 
I suspect, though, that you are correct in your assumption that accuracy is lacking. I submit to you the idea that the lack of one hole accuracy may be a function of the airgun being used as much or more than the pellet. What would be interesting to do is take an Anschutz 9003 or some such and hop it up so that it will shoot at supersonic velocities and see how much the groups change.
Are you familiar with the Daystate PCP rifles (not supersonic, 840 fps, but capable of 0.32" groups at 50 YARDS)? Or the Evanix AR series? The ARs can produce groups in the 0.4" - 0.5" range at 20 meters at velocities just under the speed of sound (.22 cal) There is a video about this at Pyramydair.com.
Pete
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