New Beast from Allen Precision Shooting!!!

[Fiftydriver]

Yes. Particularly if your dealing with rockets. Bullets don't have propulsion so the goal is to coast as efficiently as possible. Form makes bc and so does weight. The challenge comes in weather or not the loss in weight from a more slender nose offsets the loss in bullet weight. Could put a sexy secant ogive on it and lose 50g. Might be a push, maybe better or not.

I fully believe that bullet weight has A LOT more to do with BC then most believe. If you take two bullets of the exact same external design, one made of light brass alloy and the other made of a heavier alloy, the heavy bullet of same external dimensions will have a higher BC then the lighter bullet of same external dimensions.

So, yes, form is great but without mass, BC will suffer. This is one reason why smaller caliber solid bullets have such a hard time making high BC numbers, just can not get enough mass in the smaller calibers. This is not just Hammer bullets, its all solids. There is a reason why Barnes bullets do not have very high BCs compared to same weight lead core conventional bullets.

That said, the smaller caliber Hammer bullets, because of their design, can often be driven to 150 fps faster then same weight lead core bullets making up for the lower BC out to impressive ranges. Plus the terminal performance of the Hammer bullets is such that you can use a lighter bullet in the Hammer bullets and get the terminal penetration of a much heavier lead core bullet. I have found a faster then conventional twist is a good idea for straight penetration after impact but the ability to use a lighter bullet adds even more to the velocity advantages.

Once you get in the 338 bore size and larger, now you can get the mass needed to get serious BC numbers and in the larger calibers above 375, its the only way to go, much better balance of weight and length but rest assured, bullet mass has a significant amount to do with BC numbers, especially as ranges increase.

 

[Capt RB]

Very impressive Kirby!! I have enjoyed reading your posts for a long time. I hope you find the time to post up more information in the future as it is is always a must read for me!!

 

[Fiftydriver]

Very impressive Kirby!! I have enjoyed reading your posts for a long time. I hope you find the time to post up more information in the future as it is is always a must read for me!!

Thanks for your kind words!!

 

[couesaddict]

Very impressive Kirby!! I have enjoyed reading your posts for a long time. I hope you find the time to post up more information in the future as it is is always a must read for me!!

+1 from this guy! I hope the guys that questioned your video don't keep you from sharing in the future. Looking forward to the sold out of inventory. The long wait is the only thing that's held me back over the years.

 

[Fiftydriver]

+1 from this guy! I hope the guys that questioned your video don't keep you from sharing in the future. Looking forward to the sold out of inventory. The long wait is the only thing that's held me back over the years.

Anyone that knows me knows that someone questioning my results will never keep me from posting them, in fact simply gives me more chances to spread the factual based data results!!!

 

[NEMTHunter]

I fully believe that bullet weight has A LOT more to do with BC then most believe. If you take two bullets of the exact same external design, one made of light brass alloy and the other made of a heavier alloy, the heavy bullet of same external dimensions will have a higher BC then the lighter bullet of same external dimensions.

Could not agree more. Weight plays a big part in the BC. And the farther out you go the better off you are with the heavy bullet.


This wildcat is sweet as well as the bullet from Hammer Bullets! Looking forward to the testing with the 47" Barrel. Should really pick up speed! I am Enjoying this thread a lot!

New Cartridge and New Bullets. It does not get any better then that!

 

[Varminator 911]

Yes. Particularly if your dealing with rockets. Bullets don't have propulsion so the goal is to coast as efficiently as possible. Form makes bc and so does weight. The challenge comes in weather or not the loss in weight from a more slender nose offsets the loss in bullet weight. Could put a sexy secant ogive on it and lose 50g. Might be a push, maybe better or not.

Or keep all 700 gn and make the bullet an inch longer. That would require a faster twist but right now he's only talking a 12 twist barrel. There's lots of room for a longer bullet. When adding weight it doesn't all need to be longer bearing surface and a heavier bullet.

I fully believe that bullet weight has A LOT more to do with BC then most believe. If you take two bullets of the exact same external design, one made of light brass alloy and the other made of a heavier alloy, the heavy bullet of same external dimensions will have a higher BC then the lighter bullet of same external dimensions.

So, yes, form is great but without mass, BC will suffer. This is one reason why smaller caliber solid bullets have such a hard time making high BC numbers, just can not get enough mass in the smaller calibers. This is not just Hammer bullets, its all solids. There is a reason why Barnes bullets do not have very high BCs compared to same weight lead core conventional bullets.

That said, the smaller caliber Hammer bullets, because of their design, can often be driven to 150 fps faster then same weight lead core bullets making up for the lower BC out to impressive ranges. Plus the terminal performance of the Hammer bullets is such that you can use a lighter bullet in the Hammer bullets and get the terminal penetration of a much heavier lead core bullet. I have found a faster then conventional twist is a good idea for straight penetration after impact but the ability to use a lighter bullet adds even more to the velocity advantages.

Once you get in the 338 bore size and larger, now you can get the mass needed to get serious BC numbers and in the larger calibers above 375, its the only way to go, much better balance of weight and length but rest assured, bullet mass has a significant amount to do with BC numbers, especially as ranges increase.

I'm no genius about bullets. But my understanding is that BC = sectional density divided by form factor. So at the same form factor, BC is proportional to bullet weight. I don't see that as a lot more effect than expected. Increasing bullet weight has a cost, velocity. Improving form factor has no cost assuming the bullet is accurate and performs as needed. By reducing, improving, form factor you can maintain velocity and increase BC. That gives improved exterior ballistics.

The advantage of the big calipers over the small is that it takes a lot less twist to stabilize bullets of equal SD at the big calipers as compared to small. You can't get much BC with monomentals in small calipers because they can't spin up a bullet with much SD.

A 700 gn 458 bullet has SD of 0.476. You can stabilize the example above at 12 twist. A 6.5 mm bullet with SD of 0.476 would weigh 233 gn. It better be flat on both ends to stabilize with a 7 twist.

https://bergerbullets.com/form-factors-a-useful-analysis-tool/

 

[Swamplord]

Most guys just can't seem to outgrow the image of the "50 BMG" being the baddest cartridge ever, some won't even accept hard data

Good to see you back wildcatting real beasts !

reminds of the immortal 80's anthem

"Well I'm an axegrinder, piledriver"

"I want it louder .....
More power .....
I'm gonna rock ya till it strikes the hour, BANG YOUR HEAD !"

 

[Fiftydriver]

Most guys just can't seem to outgrow the image of the "50 BMG" being the baddest cartridge ever, some won't even accept hard data

Good to see you back wildcatting real beasts !

reminds of the immortal 80's anthem

"Well I'm an axegrinder, piledriver"

"I want it louder .....
More power .....
I'm gonna rock ya till it strikes the hour, BANG YOUR HEAD !"

I do like me some select quiet riot tunes for sure!!!

 

[yorke-1]

Are you worried about bolt thrust issues when pushing a BMG case head above (presumably) 60K psi? I know not all BMG actions are created equal and I'm not very familiar with the TAC50 action, so maybe the lugs are large enough to handle it.

 

[Fiftydriver]

Are you worried about bolt thrust issues when pushing a BMG case head above (presumably) 60K psi? I know not all BMG actions are created equal and I'm not very familiar with the TAC50 action, so maybe the lugs are large enough to handle it.

If the bolt opens easily, there are no bolt thrust issues. I only use a select few bmg class receivers, all more then safe with any load i would ever use in them. My loads have to prove they maintain tight primer pockets over many firings, show no significant bolt lift increase and have no extraction issues. They are plenty safe loads for any quality bolt action BMG receiver.

 

[RockyMtnMT]

Or keep all 700 gn and make the bullet an inch longer. That would require a faster twist but right now he's only talking a 12 twist barrel. There's lots of room for a longer bullet. When adding weight it doesn't all need to be longer bearing surface and a heavier bullet.



I'm no genius about bullets. But my understanding is that BC = sectional density divided by form factor. So at the same form factor, BC is proportional to bullet weight. I don't see that as a lot more effect than expected. Increasing bullet weight has a cost, velocity. Improving form factor has no cost assuming the bullet is accurate and performs as needed. By reducing, improving, form factor you can maintain velocity and increase BC. That gives improved exterior ballistics.

The advantage of the big calipers over the small is that it takes a lot less twist to stabilize bullets of equal SD at the big calipers as compared to small. You can't get much BC with monomentals in small calipers because they can't spin up a bullet with much SD.

A 700 gn 458 bullet has SD of 0.476. You can stabilize the example above at 12 twist. A 6.5 mm bullet with SD of 0.476 would weigh 233 gn. It better be flat on both ends to stabilize with a 7 twist.

https://bergerbullets.com/form-factors-a-useful-analysis-tool/

Increasing the form factor would entail slimming the nose, shortening the baring surface, etc. All of these things would result in weight loss. Then there is only one way to gain that weight back. Make the pill longer. This would result in more needed twist and dynamic stability issues. The longer for caliber a bullet gets the more they "struggle" to swap ends in flight. No matter what, weight always adds bc. Form factor can become an effort in futility.

Yes, more twist would allow us to create a heavier bullet with better bc. It will more than likely need more horse power to be more effective than the smaller bullet. It would take some experimenting. More hp behind the current design would increase the current bullets potential making it that much more difficult for the heavier, better form factor slower bullet that needs more twist to stay stable, bullet to catch up in the race.

I guess this is what drives us to find more performance.

 

[Varminator 911]

Increasing the form factor would entail slimming the nose, shortening the baring surface, etc. All of these things would result in weight loss. Then there is only one way to gain that weight back. Make the pill longer. This would result in more needed twist and dynamic stability issues. The longer for caliber a bullet gets the more they "struggle" to swap ends in flight. No matter what, weight always adds bc. Form factor can become an effort in futility.

Yes, more twist would allow us to create a heavier bullet with better bc. It will more than likely need more horse power to be more effective than the smaller bullet. It would take some experimenting. More hp behind the current design would increase the current bullets potential making it that much more difficult for the heavier, better form factor slower bullet that needs more twist to stay stable, bullet to catch up in the race.

I guess this is what drives us to find more performance.

How do we know that form factor becomes an effort in futility? I see no evidence of that. Bullets with better form continue to be developed. Witness the new Sierra HPMK with a 27 caliber ogive. Witness the 22 cal bullets we shoot now vs yrs ago when I started with a 14 twist 220 Swift. Witness the very sleek target mono bullets like Warner flatine and others now being developed.

More horsepower isn't the only way to increase down range performance. Combine hp and very sleek bullets and we will get the best possible.

There's lots of meat left on the bone when you are shooting a 12 twist barrel. I'd ask Hammer for the longest 700 grain 458 bullet they can make, longest nose and least baring surface that will shoot. And get a 7 twist barrel if that's what it takes to make it shoot.

The 2-3 mile target shooters will lead the way. Hunting bullets will follow.

 

[SealT5]

Kirby. Thanks for sharing. What you do is truly awesome. Some day I'll build a big boomer!