Quote Originally Posted by boatail View Post
Thanks everybody.. High Cap, that answers my question, as I was trying to figure out if a 1:9 will shoot a heavier bullet better than a 1:8 will shoot a light one. I want the ability to use the heavier/longer bullets, but hate to lose the ability to use the 55/62gr. loads by doing so. In a perfect world, huh? I have a Bushmaster with a 16" 1:9, so I think I'm going to get a 20" 1:8 to cover the bases. I just wish they made it in a 24" tube like the 1:9 barrel.
I'll let you know how the experiment goes when I get it all together.
At $60 for 25, I think I'd just get a .338 Lapua and reach to the next state!
with the 1:7'' twist barrel i shoot 90gr to 40gr with dime sized groups all day long... they wont be in the same spots on the target but grouping is spot on... a 1:9'' twist barrel is good for up to 70 gr for the most part. when talking about twist's the first number is the number of revolutions the bullet makes, the second is the number of inches it travels to make a revolution, the lower the number, the "faster" the twist... also to consider velocity will make up for some lack of twist, and a longer barrel will be able to more efficiently stabilize the bullet gyroscopically before it exits.

here is a chart on the twist rates vs. bullet weight (lengths).

it is more towards the bottom/middle of the page.
223 Rem + 223 AI Cartridge Guide

honestly, Sabre Defense makes a 1:8'' twist SS fluted barrel for about 375 or so IIRC on Shooting Supplies, Reloading, Gunsmithing, Hunting, Ammunition, Gun Parts & Rifle Scopes — MidwayUSA i had one about a year ago and shot wonderful, bit on the heavy side, but very accurate. that way you can shoot up to about 80gr bullets, and still be in the mid 30's for the varmint loads.

with today's bullet technology you can over-spin the lighter bullets without fearing a bullet come apart in flight, it is better to over-spin them than to not spin them enough, which would result in key-holing.