barrel twist rate question

[DrBaker]

Has anyone tried a 1:7 twist 10.5in barrel with 55gr ammo?

I want all my 223 guns to eat the exact same thing. Nobody gets a special meal around here.

 

[CAR-AR-M16]

Has anyone tried a 1:7 twist 10.5in barrel with 55gr ammo?

I want all my 223 guns to eat the exact same thing. Nobody gets a special meal around here.

I used to run my M16 with an 11.5" 1/7 barrel with 55gr all of the time. No problems.

 

[DrBaker]

I used to run my M16 with an 11.5" 1/7 barrel with 55gr all of the time. No problems.

That's good to hear. I'll give it a try. Worst case--somebody get a good deal on a slightly used barrel in the classifieds section.

 

[OStateFlyer]

Call it what you want. I call it pimptastical.

Whatever it is called, those are cool little rifles.
What upper are you using?

 

[DrBaker]

Whatever it is called, those are cool little rifles.
What upper are you using?

I'm not sure yet. I have a bad habit of changing my mind.

I've been considering working with an LMT.

 

[Buzzdraw]

Don't try to run 55 gr. and lighter out of 1-7 twist. Usually there is gray mist around 50-75 yards where the bullet blows apart. If bullet stays together, 100 yard accuracy is poor. My 1-7 loves 68-69 gr. bullets.

1-9/1-10 is a good compromise twist that will do a number of things pretty well in an AR-15/ 5.56.

 

[CAR-AR-M16]

I have not had any accuracy problem with 55gr out of a 1/7 twist barrel. I shoot Federal XM193 or WWB 55gr ammo out of my 14.5" barrel and it groups under 2" at 100yds. The range I shoot at has a 12" steel gong at 300yds and I can hit it consistantly with either of these loads. YMMV

 

[DrBaker]

I wonder if the shorter barrel had anything to do with it.

Less length, less velocity, slower spin ????

 

[grwd]

the spins the same, its just maintained at a higher rpm over a longer distance.
20" and longer barrels could blow apart a lighter bullet.

 

[DrBaker]

update:

I've been using 55gr with a 1x7 twist barrel and it works great. Now I'm happy since all my 5.56 guns are performing great with the same ammo.