Raythemanroe
Bullet Whisperer
JRS said:
Funny thing about tips, they can be made any shape or size even hollow pointed
Ray
Your pointy bullets and their flight
- Thread starter jerrysharrett
- Start date
Funny thing about tips, they can be made any shape or size even hollow pointed
Ray
dmoran
Donovan Moran
jerrysharrett said:
Now there is one of the best posts I've read in a long time..... Thanks Jerry
And in the last paragraph, a innovative concept to bullet making, that makes great sense (to me) and possibly/hopefully may inspire one of our fine bullet makers.
I new you had good input, that you hadn't yet shared..... bet there's more where that came from !.!.!
Donovan
JRS said:
You think so? Please explain...not trying to be a smarta$$ I just want to hear your basis of thinking this.
No problem Jerry. If you'll read the results Robert McCoy experienced, plus the results from the testing performed by the USAF, and also Sierra, you'll find that the bullets we use in competition have the tiny aperture in the nose, and the center of gravity towards the rear, to keep them as stable as possible in flight for longer distances, and more resistant to crosswinds.jerrysharrett said:
I don't know that much on reading what somebody else thinks but i will tell from experience that all long range bullets the weight is toward the rear ….. it has to be look at the lead line. As far as closing the the nose it shoots just as good, the smaller the better and i have closed them completely if it will let me but i am careful not to get any expansion at the shank or pressure ring……. jim
Raythemanroe
Bullet Whisperer
Good thing everyone doesn't stay with what was relevant in the past
Ray
Ray
You think so? Please explain...not trying to be a smarta$$ I just want to hear your basis of thinking this.
[/quote]No problem Jerry. If you'll read the results Robert McCoy experienced, plus the results from the testing performed by the USAF, and also Sierra, you'll find that the bullets we use in competition have the tiny aperture in the nose, and the center of gravity towards the rear, to keep them as stable as possible in flight for longer distances, and more resistant to crosswinds.
[/quote]
But what conditions have to exist to make the bullet "go to sleep". Remember it is spinning in the range of 270,000 RPM on exit.
We know the bullet has SOME wobble when it exits the muzzle so what stability factors MUST be in place for acceptably stable flight?
Ever watch a subsonic rimfire bullet on a humid morning? It appears to make a large spiraling flight. I often wonder if that is the true flight path. Same thing on contrails of heavy aircraft.
I used to be a commercial pilot, till I went blind. When we were on approach to the runway landing behind a "heavy-747 etc" just taking off the tower would announce "caution-wake turbulence from departing Boeing 747". We could actually see the vortex spiral and see them drift slowly outward.
We have seen the departing vortex spirals in the grass in front of the bench when the person adjacent fires. Is this vortex spiral we see somehow generated by an unasleep bullet or does it exist on sleeping bullets also?
.
[/quote]No problem Jerry. If you'll read the results Robert McCoy experienced, plus the results from the testing performed by the USAF, and also Sierra, you'll find that the bullets we use in competition have the tiny aperture in the nose, and the center of gravity towards the rear, to keep them as stable as possible in flight for longer distances, and more resistant to crosswinds.
[/quote]
But what conditions have to exist to make the bullet "go to sleep". Remember it is spinning in the range of 270,000 RPM on exit.
We know the bullet has SOME wobble when it exits the muzzle so what stability factors MUST be in place for acceptably stable flight?
Ever watch a subsonic rimfire bullet on a humid morning? It appears to make a large spiraling flight. I often wonder if that is the true flight path. Same thing on contrails of heavy aircraft.
I used to be a commercial pilot, till I went blind. When we were on approach to the runway landing behind a "heavy-747 etc" just taking off the tower would announce "caution-wake turbulence from departing Boeing 747". We could actually see the vortex spiral and see them drift slowly outward.
We have seen the departing vortex spirals in the grass in front of the bench when the person adjacent fires. Is this vortex spiral we see somehow generated by an unasleep bullet or does it exist on sleeping bullets also?
.
JRS said:
They would be most welcome to respond but I would like to see what the general long range shooter thinks.
Raythemanroe
Bullet Whisperer
I feel it is the spin that stabilizes the pointed VLD type bullets. I also believe the sleep happens in the barrel, others think they don't really stabilize until a couple hondo's down range.
Ray
Ray
JRS said:It isn't what others have said Jim, but rather, empirical evidence, from extremely knowledgable people
JRS, I think i'm at a level that has never reached by most as far as putting it on the target…… think about what was then and what is now. Mine is not theory, Proof is on the paper at 1000 yds. I don't buy what all is written as fact most isn't, better get out and do it and see for yourself. Ask yourself how can you put 56 shots out of 60 in the ten ring at 1000 yds. with closed meoplat and it doesn't work? evidence? Read your books and will continue to set records……….. jim
When did I say it doesn't work jim? Do you suppose luck, and near perfect conditions play a part Jim? Is it possible you might have achieved the same with open meplats Jim?johara1 said:JRS said:It isn't what others have said Jim, but rather, empirical evidence, from extremely knowledgable people
JRS, I think i'm at a level that has never reached by most as far as putting it on the target…… think about what was then and what is now. Mine is not theory, Proof is on the paper at 1000 yds. I don't buy what all is written as fact most isn't, better get out and do it and see for yourself. Ask yourself how can you put 56 shots out of 60 in the ten ring at 1000 yds. with closed meoplat and it doesn't work? evidence? Read your books and will continue to set records……….. jim
Bryan Litz Ballistics
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Cabin fever anyone...?
Bullet design is a balancing act of conflicting requirements and constraints. Every bullet design is a compromise to some extent and is determined by application.
For short range BR shooting, the optimal bullet is one that requires slower spin rates, and can be made with the best balance. Fortunately, both these requirements are met with short stubby bullets. SHort bullets require less spin, and it's easier to draw shorter jackets with low run-out consistently.
Furthermore, shooting good groups at short range doesn't depend so much on BC, so it's acceptable that the bullets have low BC's.
On the other hand, bullets that are optimized for long range performance NEED to have higher BC's due to wind sensitivity. Because of this requirement for high BC, the bullets are longer which means they suffer from greater imbalance (more difficult to draw long jackets with low run-out) AND, those long bullets need to be spun faster to stabilize.
The above is a short summary, but it sort of describes the realities of the design space for bullets made of copper and lead.
It's OK that a high BC bullet can't group better than 1/4 MOA at 100 yards because it can still hold 1/2 MOA at 1000. But take a bullet that can group 1/10 MOA at 100 and it will probably be bigger than 1/2 MOA at 1000. In other words, you're choosing the right tool for the job; short range or long range.
But getting to the OP's question; what about the future? This is something I think about all the time
To escape the confines of the current design space would mean using different materials and/or different forms of stability.
For example, at one point I looked into electroplating jackets onto cores, thinking that a more uniform jacket (lower run-out, better balanced) could be assembled one molecule at a time. Turns out the process is actually subject to many variables, and could not make more uniform jackets.
Another approach is to eliminate the biggest cause of dispersion, which for conventional rifles is due to the combination of imbalance and high spin rates. There's no getting around it; spin something at 150,000 RPM+ and even 0.0001" of imbalance is the biggest source of dispersion (in BR level rifles), and it's very difficult to balance projectiles better than 0.0001". We can change this entire dynamic by firing projectiles that are not SPIN stabilized, but instead, FIN stabilized.
Fin stabilized projectiles don't have to spin so fast, so they're not sensitive to minor imbalances. However, gun launched fin stabilized projectiles are subject to other dispersion sources, most notably launch dynamics. When you fire a fin stabilized projectile from a gun barrel, you need a sabot to seal the bore and hold the projectile. When this assembly exits the muzzle, the fins are hammered with muzzle blast which causes more tip-off than a conventional spin stabilized bullet would have. Furthermore, you have the sabot discard to consider. There are ways to address and minimize these problems, like ventalating the end of the barrel to reduce muzzle blast, but it's a whole 'nother ballgame. Consider the cost of finned projectiles/sabot assembly.
What I'm saying is there are ways to make better bullets, but they require fundamental changes and great levels of complexity compared to what we can achieve now with swaging copper and lead bullets that are well under $1/ea. And to what end? So you can shoot .05" groups at 100 yards instead of 0.10"? Heck, the bullet is 0.243" in diameter, which means there is litterally no target you can't hit with the current level of precision. For long range shooting; current equipment is capable of 1/2 MOA accuracy at 1000 yards. Which means you should be able to hit any target that's 5" or bigger at 1000 yards. But the truth is that most shooters with 1/2 MOA 1000 yard rifles wouldn't bet a beer that they can hit a 5" target at 1000 yards on the first shot every time. My point is, when the objective is hitting targets, we're not limited by precision, but we're limited by accuracy (centering the group) which isn't a matter of better bullets, but of trajectory prediction.
Only in the pure pursuit of group shooting (rather than hitting targets or score shooting) does it make sense to focus on bullet precision as the thing that needs improved.
-Bryan
Bullet design is a balancing act of conflicting requirements and constraints. Every bullet design is a compromise to some extent and is determined by application.
For short range BR shooting, the optimal bullet is one that requires slower spin rates, and can be made with the best balance. Fortunately, both these requirements are met with short stubby bullets. SHort bullets require less spin, and it's easier to draw shorter jackets with low run-out consistently.
Furthermore, shooting good groups at short range doesn't depend so much on BC, so it's acceptable that the bullets have low BC's.
On the other hand, bullets that are optimized for long range performance NEED to have higher BC's due to wind sensitivity. Because of this requirement for high BC, the bullets are longer which means they suffer from greater imbalance (more difficult to draw long jackets with low run-out) AND, those long bullets need to be spun faster to stabilize.
The above is a short summary, but it sort of describes the realities of the design space for bullets made of copper and lead.
It's OK that a high BC bullet can't group better than 1/4 MOA at 100 yards because it can still hold 1/2 MOA at 1000. But take a bullet that can group 1/10 MOA at 100 and it will probably be bigger than 1/2 MOA at 1000. In other words, you're choosing the right tool for the job; short range or long range.
But getting to the OP's question; what about the future? This is something I think about all the time
To escape the confines of the current design space would mean using different materials and/or different forms of stability.
For example, at one point I looked into electroplating jackets onto cores, thinking that a more uniform jacket (lower run-out, better balanced) could be assembled one molecule at a time. Turns out the process is actually subject to many variables, and could not make more uniform jackets.
Another approach is to eliminate the biggest cause of dispersion, which for conventional rifles is due to the combination of imbalance and high spin rates. There's no getting around it; spin something at 150,000 RPM+ and even 0.0001" of imbalance is the biggest source of dispersion (in BR level rifles), and it's very difficult to balance projectiles better than 0.0001". We can change this entire dynamic by firing projectiles that are not SPIN stabilized, but instead, FIN stabilized.
Fin stabilized projectiles don't have to spin so fast, so they're not sensitive to minor imbalances. However, gun launched fin stabilized projectiles are subject to other dispersion sources, most notably launch dynamics. When you fire a fin stabilized projectile from a gun barrel, you need a sabot to seal the bore and hold the projectile. When this assembly exits the muzzle, the fins are hammered with muzzle blast which causes more tip-off than a conventional spin stabilized bullet would have. Furthermore, you have the sabot discard to consider. There are ways to address and minimize these problems, like ventalating the end of the barrel to reduce muzzle blast, but it's a whole 'nother ballgame. Consider the cost of finned projectiles/sabot assembly.
What I'm saying is there are ways to make better bullets, but they require fundamental changes and great levels of complexity compared to what we can achieve now with swaging copper and lead bullets that are well under $1/ea. And to what end? So you can shoot .05" groups at 100 yards instead of 0.10"? Heck, the bullet is 0.243" in diameter, which means there is litterally no target you can't hit with the current level of precision. For long range shooting; current equipment is capable of 1/2 MOA accuracy at 1000 yards. Which means you should be able to hit any target that's 5" or bigger at 1000 yards. But the truth is that most shooters with 1/2 MOA 1000 yard rifles wouldn't bet a beer that they can hit a 5" target at 1000 yards on the first shot every time. My point is, when the objective is hitting targets, we're not limited by precision, but we're limited by accuracy (centering the group) which isn't a matter of better bullets, but of trajectory prediction.
Only in the pure pursuit of group shooting (rather than hitting targets or score shooting) does it make sense to focus on bullet precision as the thing that needs improved.
-Bryan
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