Originally Posted by Devestator
Thanks for the replies!
Bart B, I've always heard that the 1:12 is best for 150-168gr, and 1:10 is best for heavier rounds up to 180gr.
Rifle factory's frequently say that, but top ranked competitive shooters know better.
Favorites with the .308 Win case were/are as follows:
Palma rifle, 30 inch barrel, 155-gr bullets, 1:13 twist
22 inch barrel, 150's and 155's, 1:12 twist; what the M14 uses.
24 inch or longer, 1:12 inch barrel, normal loads, good with 168, 175 and 180's
24 inch barrel, hot loads, 1:12 twist great for 190's. (top long range performer in .308 Garands)
26 inch barrel, 1:11 twist; 168's reduced loads and max loads with 190's was very popular with match winners and record setters from 1963 to the late 1990's when 26 caliber took over in high power matches.
26 inch barrel 1:10 twist; great for 200 and 210 grain bullets.
26 inch barrel 1:9 twist, nice for 220 grain bullets.
28 inch barrel, 1:8 twist, marvelous for 240 and 250 grain match bullets.
Also, is Hornadys concentricity gauge a good investment? Its sposed to measure and correct runout. Ive switched the dies im getting to the Redding 3 die set, Redding Competition Bushing 3-Die Neck Sizer Set 308 Winchester , how are these when it comes to runout? Would the concentricity gauge be worth having if i get those dies?
Their neck sizing dies aren't as good as their full length ones. After 4 to 5 reloads per neck sized case, they've got to be full length sized anyway so their extra fat bodies don't interfere with the chamber walls and cause accuracy problems; that's why benchresters moved over to minimal full length sizing dies. Full length sizing dies make better runout on case necks and bullets 'cause they hold the case body firm and steady in one place while the neck's sized back down. http://www.midwayusa.com/product/668...308-winchester
Some top competitors use standard full length sizing dies with their necks lapped out so expander balls don't have to be used and claim they're better than full length bushing dies.
A good concentricity gauge is always good to have; it measures the physical quality of your ammo before your shoot it. Bullet runout up to 3 thousandths is not a problem if the bullets are seated out to crunch into the rifling when chambered. Otherwise, they need to be under 2 thousandths for runout.