The right twist?

[Clark_Kent_X]

for the standard AR15. what is a good twist rate for the barrel?

i was told that 1:9 was good because it can shoot a wide range of grains. but the nato standard is the 1:7

what is a good SHTF barrel....i wanna be able to shoot the widest range grain of rounds. and still have a great long lasting/heavy duty barrel

but i'm not going to shoot activly beyond 100 yrds....more like the 10-100 yrd range....if that

[DarkHorse]

There's nothing wrong with 1:9 or 1:7. Yes, 1:7 is Nato spec, but I believe that's for the 62 gr. bullets. In reality, you could shoot 45 gr. JHP's out of a 1:7 barrel, but you shouldn't have muzzle velocities over 2800-3000 fps, otherwise the bullet jacket may seperate. Varmint bullets have thinner jackets for quick expansion, whereas military FMJ rounds will stand up better to the rotationcal forces encountered at these RPM's. If you plan on sticking to 55 gr. and up (what's most commonly available), either 1:7 or 1:9 should work fine.

[Clark_Kent_X]

well i dont plan on shooting the heavier rounds. i was mainly going to stick with the 55 or 62 grain rounds

[damndave]

well i dont plan on shooting the heavier rounds. i was mainly going to stick with the 55 or 62 grain rounds

either one would be fine. i shoot a 1/9 with mainly 55 and 62gr rounds

[Clark_Kent_X]

awesome. any suggestions on what brand of barrel. i was thinking about the armalite 16"

[1lostinspace]

well i dont plan on shooting the heavier rounds. i was mainly going to stick with the 55 or 62 grain rounds

It's the length of the round that will need the right twist not just weight.
1:9 should be fine even up to 69
If I could go back I would go 1:7

[esskay]

1:8 twist with a Wylde chamber is nice. Allows you to shoot various bullet weights and also take .223 and 5.56.

[Clark_Kent_X]

not trying to do match shooting. just tactical shooting and a good fighting gun

[OutlawDon]

"The 7 twist is for the SS 110/M856 tracer bullet. A 9 twist is adequate for the ball ammo. It is marginal for 75-77 grain bullets, though, so if you want the heavies, 75-82 grains, get an 8 twist, or a 7 for the extra heavies of 90 grains from Sierra, Berger, and JLK."

"1/7 was a compromise between the M855 round that needed a 1/8 or 1/9 twist and the M856 that needed a 1/6 twist."

[1lostinspace]

"The 7 twist is for the SS 110/M856 tracer bullet. A 9 twist is adequate for the ball ammo. It is marginal for 75-77 grain bullets, though, so if you want the heavies, 75-82 grains, get an 8 twist, or a 7 for the extra heavies of 90 grains from Sierra, Berger, and JLK."

"1/7 was a compromise between the M855 round that needed a 1/8 or 1/9 twist and the M856 that needed a 1/6 twist."

that about it

so just get a 1:9 it will be cheaper and unless you plan on reloading heavy rounds then your fine.

[Clark_Kent_X]

1:9 kewl

[tacticalcity]

1:7 and 1:8 can stabalize match grade heavy ammo that 1:9 can not.

However, if you are planning on always buying the least expensive box on the shelf (55-65grain) then 1:9 is all you need.

My rifle has a 1:7 chrome lined barrel because it can shoot the 55grain ammo just fine but if I need more accuracy I can spend a little more on ammo and get it.

Of course, if you go too cheap and shoot wolf and other coated ammo you are going to mess up your barrel and it is not going to be accurate any more.

[ocabj]

I seriously don't know why people insist on 1:9 for the so-called 'SHTF' rifle. If SHTF means SHTF, then that means you'll want something that can shoot basically any .223 ammo you come across and 1:9 isn't the twist for it. 1:7" in a 20" is going to shoot everything perfectly fine. Even if you come across factory 40gr ammo, more likely than not, it's going to shoot fine and won't get enough speed even in a 20" to spin jackets off.

[DarkHorse]

I seriously don't know why people insist on 1:9 for the so-called 'SHTF' rifle. If SHTF means SHTF, then that means you'll want something that can shoot basically any .223 ammo you come across and 1:9 isn't the twist for it. 1:7" in a 20" is going to shoot everything perfectly fine. Even if you come across factory 40gr ammo, more likely than not, it's going to shoot fine and won't get enough speed even in a 20" to spin jackets off.

I agree. What I meant about varmint bullets for the most part refers to handloading rounds for max velocity, not factory ammo. Good idea to bring that up.

[Jonathan Doe]

1:9" will shoot most commercial ammo up to 69 grains well. I think it is a good twist for a barrel if one wants shoot anything 69 grains or less. My 1:8" twist barrel shoots everything well including 55 gran bullets.