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Posted: 9/21/2004 7:11:59 AM EDT
Please advise best twist rate for the 14.5 M4 Barrel,
Thanks in advance.
Link Posted: 9/21/2004 7:20:03 AM EDT
For a tactical gun, firing larger grain bullets, 1/7 is better. 1/9 can't handle the biggest 5.56 ammo. That's my understanding after 2 days in the AR world. hug.gif
Link Posted: 9/21/2004 7:48:00 AM EDT
No such thing as "best" twist rate. You want a rate for the ammo you will be shooting. Since a 14.5" barrel wont be a target/varmint gun.... you likely will want something that will shoot a wide range of ammo.... and 1/7 will shoot heavier bullets than 1/9.

If you are just going to shoot quality commercially available and imported military ammo... the majority being 55-62gr ammo, then 1/9 will do just fine. However, given the choice in two identical barrels, I will pretty much choose 1/7.
Link Posted: 9/21/2004 9:08:07 PM EDT
1/7. Why? Cause you need it to stabilize the heavier rounds.

Why do you need heavier rounds? Cause heavier=longer, and longer bullets fragment at lower velocities (like 2100 fps as opposed to 55-62 gr at 2600 fps).

You are going to have lower velocities with a 14.5" bbl as opposed to a 20" bbl, right?

You can also shoot M193 (55 gr) ammo out of a 1/7 twist.
Link Posted: 9/22/2004 11:31:06 PM EDT
Where can you find the 1:7 barrels? And what brand is good and which ones are junk?
Link Posted: 9/22/2004 11:47:55 PM EDT
Colt, LMT or Bushmaster.
Link Posted: 9/23/2004 4:33:26 AM EDT
I like 1 in 8 .......but that's just MHO
Link Posted: 9/23/2004 8:14:56 AM EDT
I just bought a 14.5" Mil-Spec barrel with 1:7 twist & a permanently attached phantom from CMMG about a week ago. I received it in about two days.

Link Posted: 9/23/2004 8:19:57 AM EDT
Unless you have some very special varminting needs, you likely won't be shooting the low weight varminter rounds that have been troublesome for the 1/7 barrels, AND the 1/7 handles all the surplus ammo pretty well AND it allows you to shoot the heavier bullets, although many 1/9 shooters have found success with the heavier rounds as well, BUT basically I don't see anything lost in getting a 14.5" barrel with a 1/7 twist. YMMV, FWIW and all other disclaimers may apply as necessary.
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