Comments on: Practical Thoughts About Transonic Bullet Stability and Accuracy

By: George Fournier

George Fournier — Sat, 04 Aug 2018 11:19:19 +0000

Forgot to mention that the altitude we conducted our test at was 1600 ft

By: George Fournier

George Fournier — Sat, 04 Aug 2018 11:17:14 +0000

We have some data on BC measurements of a prototype .338 caliber bullet we have shot to 2960 yds. What we observed was a rise in BC at extreme range, and round bullet holes. This indicates stability of the bullet traversing the transonic zone. We estimated that the bullet under the conditions of the test and a 3000 fps MV went subsonic at about 2400 yds and was stable until it hit the target at 2961 yds.

By: Slim

Slim — Wed, 24 Sep 2014 00:11:59 +0000

I tried to explain this to a marine sniper on another forum. He just laughed and said he has pictures of steel targets that were shoot by .308 from 1600 yards away. I believed him unti he said the bullet impacts where proof the bullets weren’t yawing. I know a bullet will show if it’s yawing a lot but I don’t think you can tell a difference in slight yawing. I’ll trust those pictures over splats on steel. He’s the owner of SP

By: Mikecr

Mikecr — Mon, 22 Sep 2014 22:24:34 +0000

A lot of variables. I don’t think bullet stability is easy to predict in transonic. Maybe not possible to predict.

The 80gr 224 bullet example, is a good example to illustrate. While the bullet would be unstable from the MUZZLE at 1078fps(even from 7.5in/turn), that’s not so at 1000yds. This, because bullet velocity slows way more than rotation, leading to ~3.3in/turn by 1078fps/1000yds. Sg would be around 9 there(very high).
So it’s a matter of dynamic stability, which is less than predictable, and demonstrated through field testing.

So in the end they shot good, with expected side affects of higher drag, and fixed distance.
Where this would suck is with multiple distance shooting(hunting/tactical).

By: dpaqu

dpaqu — Mon, 27 Aug 2012 19:37:44 +0000

I’ll second Bryans opinion that this is a great article. I’ve always wondered about the transonic nature of bullets and how much practical accuracy is lost.

By: Bryan Litz

Bryan Litz — Mon, 27 Aug 2012 13:57:17 +0000

Good write up!
Lots of mystery surrounding transonic instability and how it limits range for some bullets.
One item not mentioned in the write up is the effect of altitude. At sea level, especially in cold weather, the list of bullets that are transonic stable is very short. On the other hand, get up to 5,000+ feet above sea level and almost all bullets are transonic stable due to reduced air density (plus they go a lot farther before slowing to transonic speed at high altitude).
-Bryan