After reading an article in Sniper magazine from 6/13 by Todd Hodnett I have totally rethought how I look at twist rate. Todd has been doing testing on twist rate for quite some time now, granted it has been with 338LM and the 308. But he has found that buy going faster the more accurate a gun can be at long range. Now when I say long range I am referring to his test using a 308 168gr factory match grade ammunition and getting consistent hits with a “14-inch barrel and an 1:8 twist”(1). “It had no problem hitting the target multiple times at a mile”(1). While the rifles with the conventional 1:11 twist were not even making hits near the target using the same ammunition.
From his tests with the 338LM he is now finding the 1:8 twist is probably more suitable for this cartridge vs. a 1:10 or 1:11.
He also addressed the concerns about barrel life and spinning jackets off. Some have theorized the faster twist would shorten barrel life. According to Hodnett his 308 with a 1:7.8 twist had 14,000 before he changed the barrel. Oh and he is not a believer of removing all the copper from the barrel after each session. In fact he won’t do a copper removal at all unless he sees accuracy starting to diminish. Many believe that a fast twist will cause jacket core separation. A lot of this is from earlier days of shooting. But now with the advancement in bullet construction this is much less of a concern with proper bullet selection.
Granted this was all done with 308 and 338LM but I can’t imagine it would not carry over to the smaller calibers also.
If you can get your hands on a copy of the article it is a great read.
(1) Sniper Magazine 6/13 The Future of Twist Rates by Todd Hodnett p.71
From his tests with the 338LM he is now finding the 1:8 twist is probably more suitable for this cartridge vs. a 1:10 or 1:11.
He also addressed the concerns about barrel life and spinning jackets off. Some have theorized the faster twist would shorten barrel life. According to Hodnett his 308 with a 1:7.8 twist had 14,000 before he changed the barrel. Oh and he is not a believer of removing all the copper from the barrel after each session. In fact he won’t do a copper removal at all unless he sees accuracy starting to diminish. Many believe that a fast twist will cause jacket core separation. A lot of this is from earlier days of shooting. But now with the advancement in bullet construction this is much less of a concern with proper bullet selection.
Granted this was all done with 308 and 338LM but I can’t imagine it would not carry over to the smaller calibers also.
If you can get your hands on a copy of the article it is a great read.
(1) Sniper Magazine 6/13 The Future of Twist Rates by Todd Hodnett p.71