New Beast from Allen Precision Shooting!!!

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 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 becomes a point where it becomes an effort in futility. Remember we are dealing with a bullet with a sectional density in the .477 range, thats just insane already. To get much more aggressive in form factor, as mentioned, you would need to have to start sacraficing in other areas such as baring surface and drive band width which would likely result in creating other potential issues such as stability and the ability of the drive band to hold the lands.

Again, remember, these are 700 gr. Class bullets in a 458 cal bore. So far outside the relm of any 27 or 224 bullet that its not even remotely possible to compare the three.

In those instances, the standard twist for the 27 has been 1-10 forever. In fact i will step out and say I was the first to promote extreme performance 270 cal bullets way back when i had Wildcat Bullets make me the first 169.5 gr uld rbbt and then the monster 195 gr uld rbbt for my 270 Allen magnum. We were using 8 twist barrel.

Point being the 270 family of bullets has A LOT OF ROOM FOR IMPROVEMENT from the commercial bullet makers.

We pretty much started at the extreme with the 700 gr hammer in a 458 bore, we did not work up to it. I told them the line i wanted to push to and they pushed right up to that line of stability.

In the 224 family, 1-14 has been standard forever, however now its common to see as fast as 7 twist in the 223 rems and 5.56 rifles. However, these twists and bullets used in the really fast 224 cals pose other problems such as bullet integrity and survival of rpm levels.

Again, a 700 gr 458 cal bullet has A LOT of bullet mass ahead of the front drive band. This can cause some serious problems if you go to far. With the front drive band design we used its even more of an issue. When you have as much mass ahead of the drive band as this bullet has and when your dealing with velocity levels we are, and in relatively fast twists, the massive bullet wants to resist the forces of rotation from the rifling. Thats why we need to get these bullets rotating the instant they start moving down the bore. If they do not, a huge amount of shear stress will be imparted to the drive bands and possibly shear off that drive band and you have total accuracy failure.

So, yes we can increase the aggressiveness of the ogive, but in the process, you sacrifice some of the support contact area the bullet body has to control and hold the rifling. As such, the risk of shearing goes up.

You can also easily add length to the bullet, and easily increase twist rate to handle the length, however, you out more weight or mass ahead of the drive band and the more aggressive twist makes live even harder for the bullet to hold the lands. Heavier buller resists rotational forces more, faster twist exaggerates stress on drive bands......

Once you reach the limit of the alloy the bullet is made of, you reach futility.....

Simply put, there is alot of room for improvement in the two calibers you list, i fully agree there have been huge advancements, i will say they are still far behind what we started using over 13 years ago in my 270 Allen Magnum but there have been major improvements.

With this 458 project, we wanted to push the max limits from the start, not alot of room for improvement being more aggressive.

Also, with ogive design, if you look at the berger bullets, the hybrid designs usually have a higher BC then the VLD designs even though the VLD design seems more aggressive in shape. The longest sharpest ogive does not nessesarily mean a gain in BC.....
 
There becomes a point where it becomes an effort in futility. Remember we are dealing with a bullet with a sectional density in the .477 range, thats just insane already. To get much more aggressive in form factor, as mentioned, you would need to have to start sacraficing in other areas such as baring surface and drive band width which would likely result in creating other potential issues such as stability and the ability of the drive band to hold the lands.

Again, remember, these are 700 gr. Class bullets in a 458 cal bore. So far outside the relm of any 27 or 224 bullet that its not even remotely possible to compare the three.

In those instances, the standard twist for the 27 has been 1-10 forever. In fact i will step out and say I was the first to promote extreme performance 270 cal bullets way back when i had Wildcat Bullets make me the first 169.5 gr uld rbbt and then the monster 195 gr uld rbbt for my 270 Allen magnum. We were using 8 twist barrel.

Point being the 270 family of bullets has A LOT OF ROOM FOR IMPROVEMENT from the commercial bullet makers.

We pretty much started at the extreme with the 700 gr hammer in a 458 bore, we did not work up to it. I told them the line i wanted to push to and they pushed right up to that line of stability.

In the 224 family, 1-14 has been standard forever, however now its common to see as fast as 7 twist in the 223 rems and 5.56 rifles. However, these twists and bullets used in the really fast 224 cals pose other problems such as bullet integrity and survival of rpm levels.

Again, a 700 gr 458 cal bullet has A LOT of bullet mass ahead of the front drive band. This can cause some serious problems if you go to far. With the front drive band design we used its even more of an issue. When you have as much mass ahead of the drive band as this bullet has and when your dealing with velocity levels we are, and in relatively fast twists, the massive bullet wants to resist the forces of rotation from the rifling. Thats why we need to get these bullets rotating the instant they start moving down the bore. If they do not, a huge amount of shear stress will be imparted to the drive bands and possibly shear off that drive band and you have total accuracy failure.

So, yes we can increase the aggressiveness of the ogive, but in the process, you sacrifice some of the support contact area the bullet body has to control and hold the rifling. As such, the risk of shearing goes up.

You can also easily add length to the bullet, and easily increase twist rate to handle the length, however, you out more weight or mass ahead of the drive band and the more aggressive twist makes live even harder for the bullet to hold the lands. Heavier buller resists rotational forces more, faster twist exaggerates stress on drive bands......

Once you reach the limit of the alloy the bullet is made of, you reach futility.....

Simply put, there is alot of room for improvement in the two calibers you list, i fully agree there have been huge advancements, i will say they are still far behind what we started using over 13 years ago in my 270 Allen Magnum but there have been major improvements.

With this 458 project, we wanted to push the max limits from the start, not alot of room for improvement being more aggressive.

Also, with ogive design, if you look at the berger bullets, the hybrid designs usually have a higher BC then the VLD designs even though the VLD design seems more aggressive in shape. The longest sharpest ogive does not nessesarily mean a gain in BC.....
Thank you for your response. I've made the point I intended. All I'll add is that I'm sure that despite the law of diminishing returns and chances for outright failure, bullet form will continue to improve. Twenty yrs from now we'll be shooting longer, sleeker bullets than we are now.
 
Last edited:
Thank you for your response. I've made the point I intended. All I'll add is that I'm sure that despite the law of diminishing returns and chances for outright failure, bullet form will continue to improve. Twenty yrs from now we'll be shooting longer, sleeker bullets than we are now.
Since I am Hammer Bullets I'll make you a deal. You build the rifle and I'll make the experimental bullets to see if we can improve the potential. I never said you were wrong, I'm just not sure.
 
Since I am Hammer Bullets I'll make you a deal. You build the rifle and I'll make the experimental bullets to see if we can improve the potential. I never said you were wrong, I'm just not sure.

Make a bullet for Kirby that is heat seeking so he'll stop missing so many big whitetails...
 
Since I am Hammer Bullets I'll make you a deal. You build the rifle and I'll make the experimental bullets to see if we can improve the potential. I never said you were wrong, I'm just not sure.
So I did a little figuring. How about a 7 twist 300 PRC. That should stabilize a 2 inch long copper bullet. Make it 200-210 gn which would require a form factor of 0.75 to 0.79 in order to reach G7 BC of 0.4. Would that have enough meat in the bearing surface to possibly shoot well?
 
The problem is the bullet length to caliber. The dynamic stability of projectiles that push 7x caliber in length get nearly impossible to stabilize. Looks good on paper but not so good whenthey make oblong holes in the paper.
 
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.

Good to know. I held off on building a 458/416 Barrett improved wildcat based on accounts from multiple 50 BMG bench rest shooters how advised me that size and design of the BMG case head required them to be limited to 60K psi or less. This was some time ago and based on their experience with actions like the AR-50. I've very interested to see how this works out for you.
 
Good to know. I held off on building a 458/416 Barrett improved wildcat based on accounts from multiple 50 BMG bench rest shooters how advised me that size and design of the BMG case head required them to be limited to 60K psi or less. This was some time ago and based on their experience with actions like the AR-50. I've very interested to see how this works out for you.

Thats right where i estimate i am loading to, 60k psi and i agree, should not load higher then that. I will also state i recommend only using RWS, certainly not cheap mil surplus brass which can range widely in quality.
 

Recent Posts

Top