Barrels 101

[C4IGrant]

I understand how it is made, question is what should I expect from two identical carbines where one has 1/7 and another has 1/9 twist? If nothing then why some manufacturers adopt 1/9 while other 1/7?

Well it depends on several things. For instance, a 1/7 twist barrel shoots 55gr ammo very well to about 100yds. Past that we see the groups open up a lot. Same with the 1/9 twist barrels. At about 100yds, 75/77gr ammo does pretty well, but as you go farther out, your group sizes can open up.

So if you want to shoot heavier grain bullets at distances over 100yds, stick with a 1/7 twist barrel (which is what I shoot).


C4

[isakhnov]

Well it depends on several things. For instance, a 1/7 twist barrel shoots 55gr ammo very well to about 100yds. Past that we see the groups open up a lot. Same with the 1/9 twist barrels. At about 100yds, 75/77gr ammo does pretty well, but as you go farther out, your group sizes can open up.

So if you want to shoot heavier grain bullets at distances over 100yds, stick with a 1/7 twist barrel (which is what I shoot).


C4

Thanks, that makes sense. I'm not planning to go long with the carbine and will be looking at .308 for that purpose some time later (and that opens another set of questions but probably for a different board )