AR Sponsor
Posted: 9/9/2007 4:27:06 PM EDT
You'll usually only find 1/12 twist rates on 20"+ longer barrels - most of which I've seen on 24" stainless steel varmint barrels (but other configs do exist). Shorter than that and you won't have the barrel length necessary to stabalize a bullet with that slow a twist rate. _MaH |
1/12 twist can be found on m16a1 barrels. I don't know if anyone currently making a 1/12 barrel, so a surplus barrel would be your best bet. |
|
Rock River Arms is the only place I could find which had a 1/12 twist. I'm not saying there aren't others out there, but this is the only one I could find. Rock River Arms Stainless Steel Varmint Barrel Assembly, 24 Inch 1:12 Twist _MaH |
1/9 is a great compromise twist rate, most of them will stabilize from 45-62 gr bullets very well. You start going to faster rates and you start raising the weight (well length, but one leads to another) that stabilizes best. Go slower and you lower the weight bracket. The 1/12 does an excellent job on the varmint weight bullets, but it is pretty weak with anything else. Decide if that is what you want to stick with before going that way. |
|
The best reasoning for choosing the faster 1/7 twist rate is that by shooting the heavier 77 and 75 grn bullets one cannot no only increase the effective range of carbine rifles but the lethality of the mouse gun at those longer ranges. YMMV, but I want my AR15 carbines to be shooting the baddest bullets possible as accurately as possible and yet give up nothing to the 1/9 twist barrel choices when shooting the lighter 40-55 grn rounds. The 1/7 twist in 14.5" and 16" rifles is the ticket for meeting my requirements, your requirements may vary....  mike |
AR Sponsor