Bullet stability

[xsn10s]

I understand that B.Litz is the go to expert on the ballistics subject but isn't there another unaffiliated engineer that could give fresh/different views? Nothing against Litz but if you keep asking the same person similar questions wouldn't you expect similar answers? Believe me, I'm no engineer but just like at 1 time all we needed was B-1 ballistics models. We have learned some things that not so long ago people thought were impossible and have had to come up with a B-7 ballistics model because a projectile with a BC of over 1.0 was thought to be unattainable. I hope that I said that right.

Why wouldn't you go to the leading expert?

If I have a bullet that is close to stabilizing, say it needs 9" twist and I have a 9&1/2 twist barrel would increasing the velocity (bullet rpm) help stabilize it? I realize that the bullet will still have the same rotation to distance ratio but can it be fooled?

I'm not trying to be a jerk here but you can pretty much answer this yourself. Plug in your data on this barrel twist calculator and it show you your stability. Not sure what you mean by bullets being "fooled". I'd say not hey can't. But bullet's contact with the barrel will be a factor in stability and accuracy. As is barrel condition such as throat erosion. There are all kinds of variables: altitude, air density, velocity, but first things first. Try out the barrel twist calculator.

Twist Rate Stability Calculator

Our newly updated Twist Rate Stability Calculator not only tells you what your SG is, but it also lets you know if you are reaching your optimized BC.

bergerbullets.com

 

[scpaul]

I've pretty much accepted that you can't fudge the ballistics enough to really matter. Now I'm thinking about how external ballistics would affect a different configuration projectile.

 

[xsn10s]

I've pretty much accepted that you can't fudge the ballistics enough to really matter. Now I'm thinking about how external ballistics would affect a different configuration projectile.

I'd say the study of external ballistics doesn't affect a different configuration projectile. But rather the bullet's/ projectile's design or configuration has certain characteristics. And the science of aerospace engineering would give you the highest probability of predicting that projectile's characteristics.

 

[Hugnot]

Put pop out fins on the bullets & give them a little boost with some solid propellant fuel & forget about twist rates.

 

[scpaul]

I don't think that we need to revisit the "Gyro Jet", do you?

 

[Mike Matteson]

Think of something like a wad cutter shape or a beer can, but not bud light.

Don't forget Miller Light. They joined the club and double down.
Interesting discission, learning something at the same time. A lot of it is way over my head.

 

[scpaul]

Mike, mine too. I learn something from every discussion that I engage in. I think that's what it's all about.

 

[Mike Matteson]

Mike, mine too. I learn something from every discussion that I engage in. I think that's what it's all about.

Got that right. Lots to be learn or improved on. i had just started out have firing springs replaced. Order out some more this moring. My last rifle I already had the spring replaced. Several I hadn't but will now. Some are in my sons rifles. Never to old to learn. and any time I learn something new it's a great day.

 

[scpaul]

Are you going to a stronger spring and a lighter firing pin?

 

[Zen Archery]

If I have a bullet that is close to stabilizing, say it needs 9" twist and I have a 9&1/2 twist barrel would increasing the velocity (bullet rpm) help stabilize it? I realize that the bullet will still have the same rotation to distance ratio but can it be fooled?

Correct me if I'm wrong but aren't TR based off minimal TR or faster? Your 1/2 TR should be well within stabilization range. As for faster velocity for to stabilize it did not work for me. Bullet published 1:7 TR and I had 1:8 TR.
Here were the results…

Can you define a ballistician? What qualifies one to be a ballistician? Is there an actual degree for being a ballistician? What does a ballistician do that you wouldn't do to find the answer to a ballistics question?

I tried looking and the only degree I could find was in forensics. Something like physics maybe. In the end ballisticians dream it up and then go and test it to see if it works. Just like all of us here.

Steve is right. Ballistics degree is a forensic science degree.

The two people I know with PH.D's in fluid dynamics and environmental fluid mechanics, who shoot with me occasionally, find ballistics pretty elementary level mathematics. They're not wrong. The modern bullet (and other rifle projectiles) design has pretty much remained the same since the 1830's (with a million design tweaks from then to now). Ballistic mathematical models were available by WWII. Pretty effective during Desert Storm. And we have those mathematical models in the form of Apps in 2023.

Attempting to break the laws of physics can be fun but I'd start by trusting old data first.

Someone get back to me about minimal TR or faster.

 

[scpaul]

I think that the biggest change is just that we improved the projectile enough to warrant the G7 ballistics measurements.

 

[scpaul]

Oh, by the way that's one of the prettiest keyhole that I've ever seen. Way better than mine. The vapor trail is unusual, I'd read that the Hammers would do that but that's the first time that I've ever seen it.

 

[Zen Archery]

100 yard keyhole accuracy not too bad.

 

[BigDon]

I bet forming a bullet that shape would be a problem atleast according to the big bullet makers. They would probably be worried about acceptance and recouping costs.

Maybe not! The basic design concept discussed here is exactly the same as the now-well proven bulbous noses on almost all heavy ships - including the Navy!