Pistol barrel twist rate...

[JColumbus]

Is 1:10 really that much more accurate than 1:16 for 9mm 115 124 grain? I have done a lot of research on this matter to come to a better understanding. I wanted to see what you all had to say about the matter. Even if it IS more accurate, is it enough for an average shooter like me to notice?

 

[Charlie]

The real answer would need to come from bullet manufacturers that have conducted tests. My personal opinion is that slight differences would not be noticeable by us average plinkers. I'm also guessing that hunters using pistols for longer ranges (50 to 100 yds.) might be affected by differences in twist. Just my best guess.

 

[Dred]

Without measuring bullets and doing the math ... either will stabilize 124g and "shorter" (weight of bullet is commonly used as substitute for length; length of bullet is what stabilizes it). I enjoy shooting 147s - I'll keep my 1:10s.

This can be estimated mathmatecally and I'm making a guess. If you need the math - I can deliver it later.

 

[Charlie]

Without measuring bullets and doing the math ... either will stabilize 124g and "shorter" (weight of bullet is commonly used as substitute for length; length of bullet is what stabilizes it). I enjoy shooting 147s - I'll keep my 1:10s.

This can be estimated mathmatecally and I'm making a guess. If you need the math - I can deliver it later.

Exactly correct! ^^^^^^^

 

[JColumbus]

The real answer would need to come from bullet manufacturers that have conducted tests. My personal opinion is that slight differences would not be noticeable by us average plinkers. I'm also guessing that hunters using pistols for longer ranges (50 to 100 yds.) might be affected by differences in twist. Just my best guess.

That's something I've read a lot of people feel. When I spoke to the S&W tech, he made it seem as if I'd be making a mistake to "downgrade" to 1:16, as if there WAS a big difference.


Thanks for the replies guys. The thing is, S&W tell me that the new 1:10 twist they now use on the 9mm CORE, is more accurate than the 1:16. Storm Lake tells me that their barrels are a lot more accurate than S&W factory barrels, but they only make 1:16 twist. The information is conflicting. I wanted to get a .40 CORE and a 9mm conversion barrel. If S&W is correct, the 9mm Storm Lake barrel will be less accurate than if I were to get a 9mm with a factory 1:10. If Storm Lake is correct, my M&P CORE 9mm will be less accurate than a .40 with their 9mm conversion barrel. Hours of research have also revealed conflicting information. So I don't know if I should get the .40 and a conversion barrel, or just get the 9mm. I will rarely shoot .40 out of it, but may as well have that capability if I ever chose to. See my dilemma? Even if nobody can help me with the twist rates and accuracy, a different perspective may help me see a point, or reason in a way that can help me make a solid decision. For now, I'm going with the 9mm.

 

[Charlie]

I think you're over-thinking it. Twist rates have to do with the length of the bullet (usually determined by weight) and determines how much the bullet is stabilized. It's either stabilized or it's not. If it's not, a keyhole effect will show up when it hits the target. Different calibers cannot be compared regarding twist rates. A 9mm bullet that stabilizes well with a specific twist rate in a 9mm barrel may or may not be as accurate as a .40 caliber bullet that stabilizes well in a .40 caliber barrel. And the whole ideal of stabilization in a pistol caliber is much less sensitive than in a rifle caliber designed to go a lot further and be a lot more accurate. One could shoot a 9mm (or .40 cal.) from a pistol with a specific twist rate and have great accuracy, then change the twist rate and also have great accuracy, or poor accuracy. There are a great deal more variables involved than twist rate.

 

[JColumbus]

Haha. I am told I over think things all of the time. I do. Thanks for clearing it up for me. I ended up telling the guy that I'd go with the 9mm but now it seems I should have chosen the .40. But then there is the fact that it may be a long while before I get my hands a conversion barrel. Partly due to funds, but mostly to availability of them. What would you do in my case?

 

[navyguy]

Don't forget to factor in bullet speed. For example, +P+ 124 grain 9mm would probably stabilize better with 1-16 rifling, and a 147 grain loaded light, as in target ammo might benefit more from a faster twist rate. In the end though, at normal shooting distances generally seen with pistol shooting (3-25 yards, with the vast majority done at 7-10 yards) I doubt accuracy differences would be noticeable. You get more accuracy variance when you shoot cheap target ammo like WWB.

 

[Charlie]

I'd stop worrying about it. At 25 ft., with any pistol, on any given day your groups can be completely different based on weather, the ammo (hand loaded or commercial), time of day, and most of all, how the shooter feels that day. Twist would be one of my absolute last concerns (with a pistol).

 

[Charlie]

Don't forget to factor in bullet speed. For example, +P+ 124 grain 9mm would probably stabilize better with 1-16 rifling, and a 147 grain loaded light, as in target ammo might benefit more from a faster twist rate. In the end though, at normal shooting distances generally seen with pistol shooting (3-25 yards, with the vast majority done at 7-10 yards) I doubt accuracy differences would be noticeable. You get more accuracy variance when you shoot cheap target ammo like WWB.

Absolutely! And even those differences (if the shooter does the right things) would still be well within "minute of thug"!

 

[IXLR8]

I have a 5" CORE 9mm, and can attest to the extreme accuracy the Storm Lake barrel provides. The barrel is stainless with threads. I can shoot this gun more accurately than my Sigs, which are very accurate. The barrel did take 12 weeks to receive. It feeds personal defense ammo flawlessly.

 

[JColumbus]

Absolutely! And even those differences (if the shooter does the right things) would still be well within "minute of thug"!

Minute of thug?

 

[JColumbus]

I have a 5" CORE 9mm, and can attest to the extreme accuracy the Storm Lake barrel provides. The barrel is stainless with threads. I can shoot this gun more accurately than my Sigs, which are very accurate. The barrel did take 12 weeks to receive. It feeds personal defense ammo flawlessly.

Wow! Can you say the same with the factory barrel in it? Thanks.