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View Full Version : Barrel Twist and Bullet Weights


CrossedRifles
04-23-2011, 8:32 PM
So for my AR-15, many people recommend a higher grain bullet, such as a 77 Gr. Sierra BTHP, because technically they say the twist 'stabilizes' it. I have noticed the gun shoots much more accurate with the 77 Gr. also.

So my question is, does the barrel twist and bullet weight play any role in handguns?

Can my Sig Sauer P226 with a barrel twist of 1 : 10 handle a 147 Gr. bullet?

pontiacpratt
04-23-2011, 8:48 PM
So for my AR-15, many people recommend a higher grain bullet, such as a 77 Gr. Sierra BTHP, because technically they say the twist 'stabilizes' it. I have noticed the gun shoots much more accurate with the 77 Gr. also.

So my question is, does the barrel twist and bullet weight play any role in handguns?

Can my Sig Sauer P226 with a barrel twist of 1 : 10 handle a 147 Gr. bullet?

I could be wrong but the distances that a handgun is effective and used for twist really isn't that important. I'm sure the ballistic gurus will have a real truth.

locosway
04-23-2011, 11:05 PM
It has nothing to do with bullet weight. The difference on the AR has to do with the length of the bullet. The tracer rounds had a longer bullet (and more weight), which needed more twist to stabilize them.

For a handgun, the distances involved are very short generally. While twist does matter, it just doesn't matter enough.

BamBam-31
04-23-2011, 11:08 PM
depends on who you ask. for most shooters, it doesnt matter. for competitors or guys wanting super accuracy, it does. lots of info over on enos forum.

Shenaniguns
04-24-2011, 4:34 AM
The M&P has a semi-retarded 1:18.75 twist which is slow for 9mm and can make it picky with slower 9mm, in my testing this seems to be true and is one reason Apex and Bar-Sto are working on a 1:16 twist barrel. S&W engineers went with this twist for longevity and velocity which is silly IMO as I'd rather have a proper twist that suits more variety of 9mm bullets and less life (Say 50,000 rounds instead of 75,000).