Home Forums Hunting & Shooting Hunting Rifles Does anyone think a faster twist helps with terminal performance?

You hear it quite a bit that a faster twist than what's necessary to fully stabilize a bullet in flight, helps with terminal performance once the bullet hits game. So for example, if perhaps a 9 twist gives a particular bullet an Sg of 1.5 or more, would an 8 twist give better terminal performance than the 9 twist once the bullet strikes game? I'm interested in what y'all think or better still, have experienced.

Um, no.

Perhaps in light weight varmint bullets which are pretty fragile to begin with...

Depends.
Is the game inhaling? Or exhaling?
😳

Either one.

nope

So I suppose the theories could be along the lines that with a frangible bullet the faster twist might disperse the pieces further and faster and cause more damage, and with a non frangible bullet the extra spin may help it in a denser medium, perhaps. I'm not saying these theories are valid, just putting it up for discussion.

You’re talking ~ 12% difference in rpm.

Yet a 12 % difference can make a big difference in stability during flight (at the margin), so its not unreasonable to speculate whether it makes a difference in terminal performance.

Too fast or too slow a twist for a selected bullet is never a good thing

No. SG in the atmosphere has nothing to do with terminal ballistics.

We know the effects of too fast or too slow a twist for a selected bullet in flight, but the ideal twist for a bullet once it strikes game which is considerably different to the medium of air, doesn't seem to have been studied much, or if it has, I am not aware of the findings.

Heres some of my observations of rifling twist:

Had a 1:9.5" rifling barrel on a 9.3x62. With 300 grain swift-aframes, the recoil was stout.

In a 9.3x62 with a 1:14", the recoil was less, and those same 300 grainers recovered from moose and caribou shot a 400-500 yds expanded wonderfully.

In a savage 99 308, with 1:12 rifling, some 200 grain bullets would key-hole the target.

In a ruger 308 with 1:10 rifling, itll stack those same 200 grainers into quarter inch groups.

Grabbing some popcorn…

I tend to like more RPMs myself. Old Bill Steigers was a nut about RPMs with his Bitterroots, shooting a lot of them into media and believed the faster they turned the better they worked.

Probably doesn’t matter much, but I’ll always take more RPMs vs just enough.

And that's the thing, I've heard the same thing from several very experienced hunters to not just dismiss it as fallacy.

Watch some ultra slo-mo videos of projectiles hitting gelatin and you can see creases in the gelatin caused by the deformed bullets. See if you can see how many revolutions the bullet makes before it stops.

It matters in both directions.

The original AR-15 had a slow for cartridge 1-12 twist and bullets would tumble enhancing the termial performance of M193.

Ross Seyfried told me he prefered a 1-10 or 1-12 twist on his .416 Remington as solids would penatrate straighter and not tumble. I think he may have convinced Remington to go to a tighter twist than the original 1-14.

A fast twist does have epanding bullets expanding a bit faster.

I think so myself John. Very familiar with the AR’s and once the 1-7’s and 77 SMKs were available those were game changers.

And yeah, it makes sense on the big guns too, as a stabilized bullet should stay on point better than a marginal one.

I think it’s a cool topic myself. Never seen many folks say “man, I wished I had a slower twist cause my bullets went too straight”. Maybe back before before bullets were so good, but it doesn’t seem like a thing nowadays.

Is the OP referring to increased rotation creating more centrifugal force which tears a bullet apart more and thus causing more damage—-or just more rotation causing a bullet (or the shank if it expands) to penetrate straighter?

Not sure, but I tend to think both occurs because of RPMs.

But I am still learning so I like to hear others thoughts.