I have been reading through these forums and also doing some research online about ammunition for the Ar15. When I looked on RRA's website, it states that my rifle has a 1:9 twsit, however, in the instrcution manual it states the barrel is 1:7. Anyone have any insight on this?

The twist should be stamped on the barrel.

Wow! Guess it pays to look. Thanks man. It is a 1:9.

That's a fairly fast twist rate FYI.

That's a fairly fast twist rate FYI.

Thats a pretty standard twist for alot of AR barrels, most stainless barrels are 1:8, and most of the others like BCM, DD, Colt, Spikes etc use a 1:7 twist.

Well, according to one site, a 1:9 is more forgiving to different types of ammo. I am not sure if this is true, but that is what I read. It was recommended that 193 be used for closer range, while 855 was rtecommended for over 200 yards. Again, if anyone has any info or opinions, let me know.

Her is a chart for bullet weight vs barrel wist rate.

http://www.shilen.com/calibersAndTwists.html

 

If you scroll down t0 .224 you'll see roughly what your ideal bullet weight range is.

If you shoot 55gr, you want a 1/9 or 1/8. if you shoot +65gr you want a 1/7.

You want the bullet to have as much spin as possible with out sacrificing the structural integrity of the bullet. The more spin, the more stable it is in flight.

What rifle do you have from them. MY operator2 has a 1/9 heavy barrel. Wish they used a lightweight, and they never specified when i ordered.

Well, according to one site, a 1:9 is more forgiving to different types of ammo. I am not sure if this is true, but that is what I read. It was recommended that 193 be used for closer range, while 855 was rtecommended for over 200 yards. Again, if anyone has any info or opinions, let me know.

Eh. xm193 will do anything range wise xm855 can do. Xm855 is AP green tip, while 193 is plain FMJ. The only real difference is penetration.

Ok, so either of those rounds would be fine for SHTF or range shooting? I have the tactical operater LAR-15. It is a 1:9 twist. I am just trying to learn as much as I can about the right ammo to use and for what. Ar is a new platform for me, and I like to know as much as I can about anything I own. I appreicate the tips and info guys.

Yes either will be fine.

Ok, so either of those rounds would be fine for SHTF or range shooting? I have the tactical operater LAR-15. It is a 1:9 twist. I am just trying to learn as much as I can about the right ammo to use and for what. Ar is a new platform for me, and I like to know as much as I can about anything I own. I appreicate the tips and info guys.

 

In SHTF, you can shoot anything out of a 1:9. Accuracy will suffer on 72 or so grain or heavier bullet but it'll still kill. The bullet will start to tumble earlier that it would have otherwise.

 

Most cheap ammo is 55gr so a 1:9 twist is fine.

RRA suggests no break in for this barrel, as it is done by them before it is sent off. I just purchased an Eotech setup for it and plan to get to the range soon to zero it and actually get used to firing it. Anyone suggest any place to buy ammo? At least I know what to get now.

The-armory or sgammo usually have pretty good prices, but shop around.

 

http://www.the-armory.com/shopsite_sc/store/html/223_ammunition.html

 

http://www.sgammo.com/catalog/rifle-ammunition/223-556mm

surplusammo.com usually has xm193 in stock at a decent price.