Trying to set up my hold points for my Ruger No. 1 in 450 Bushmaster for hunting.  I don't have a chronograph so I can't get readings, but I am wondering how great of an effect a faster twist will have on velocity?

450 Bushmaster rifles typically come with a 20" twist, but mine has a obscenely fast 10" twist.  I shoot 250gr FTX for hunting, and they typically do 2200 FPS out of a 20" barrel with a 1:20" twist.  Wondering what kind of gains I'd see using the 10" twist?

Twist doesn't impact velocity a whole lot, but in theory a faster twist would result in lower velocity all things being equal.



http://bulletin.accurateshooter.com/2015/02/does-barrel-twist-rate-affect-muzzle-velocity-litz-test/#:~:text=After%20all%20the%20smoke%20cleared,a%201%3A8%E2%80%9D%20twist

The only way you’re going to get more velocity is through a longer barrel, higher powder load in the cartridge or using a lighter projectile.  And with all of those, there is a finite level to which they can progress before you run out of gains.

Are you sure of the twist on the #1?  That's really fast.  What is stamped on the barrel?

Yep!  I thought it was a type at first when I saw it on a few websites.  The barrel doesn't have the twist rate stamped on it, though.  On Ruger's website they have a video showing the exact same gun off and the Ruger rep even says it is a 1:10 twist.

My guess is it's so fast because I've seen Hornady now has a 395gr subsonic load for the 450 BM, and another manufacturer has a 425gr sub load.

I did find a guy who tested the No. 1 in 450 BM and he recorded velocities, and the average was just slightly under manufacturer velocities.  The 250gr FTX which is what I shoot out of it does 2200 fps out of a 20" barrel according to Hornady, the guy who tested the No. 1 said his average with that load was 2,197.  So it seems the twist had almost no effect on velocity.