Thread: Can twist rate be too fast?

This kinda pre-dates dially scopes when if you wanted to hold fur to 400 or whatever, you needed a faster flatter shooting cartridge. Hence 270 was standardised around 130gr (which only needed a 1:10 twist) and 22-250 got a 1:12 or 1:14. 25-06 will no doubt be similar. Yeah this definitely had an added benefit of providing some insurance against bullets blowing up... but I don't think it was the primary reason.

Nowadays, to get a 270 to perform well beyond 400 out to long range like something such as a 6.5 PRC, it'd need a similar 1:8 twist and a ~165gr bullet.

The difference in pressures and speeds with something like a 55gr bullet in a 223 are pretty negligible between 1:12 and 1:7. Most bullets can hold up to some pretty extreme amounts of spin too - I've got a fast twist 22-250ai and so far no blow ups with the lightweight bullets at 4k+ and 400,000rpm either... though I'm sure it's just a matter of time as the barrel rapidly wears out

Originally Posted by MB

I've often heard about twist rate being too slow for heavy projectiles, but what about too fast for light projectiles? I'm thinking .308 16.5 inch barrel with 1:8 twist and 125gr projectiles? Cheers.

The standard 1:12" twist will handle bullets from 110 grain to 180 grain no real point going to a faster twist some use 1:11" barrels for 175 to 190 grain match bullets,
The Full bore shooters use 1:13" and 1:14" barrel goethe 155 grain match bullets they have to use,
I have a .300 BLK and three .308"s with 1:13" barrels main diet is cast bullets but they will handle 168 SMKs have some 175 SMK's to try,
You only need a 1:8 to shoot super heavy bullets subsonic.