Cast in 16" AR-15 works great for....do I dare try an AR-15 pistol and cast?

[cpy911]

Hi all,
I am casting and happily shooting cast RCBS 22-055-SP out of my AR with a 16" barrel and 1:9 twist, running about 2000 FPS. Everything works great, good accuracy for my plinking purpose (1-2 MOA) and great function. I run about 20.2 gr of IMR 3031.

Anyhow, I would like to build a pistol AR with a 10.5" barrel. Would my load even work? The slowest 10.5" barrel twist I can find is 1:9.

My question is, if I shoot this load with a 1:8 twist in a 10.5" barrel, will I have any chance for accuracy? Looking for 1-2 MOA.

Thanks,
cpy911

[petroid]

I haven't shot cast out of my 223 AR15, but it is a 1:7 twist and shoots 50gr bullets just fine. At your velocities I think it should work, as long as you can get the action to cycle. You don't have much dwell time on a 10.5" barrel with a carbine gas system. You may need pistol gas length. But if it's a pistol barrel, it probably is already.

[3jimbo3]

Hi all,
I am casting and happily shooting cast RCBS 22-055-SP out of my AR with a 16" barrel and 1:9 twist, running about 2000 FPS. Everything works great, good accuracy for my plinking purpose (1-2 MOA) and great function. I run about 20.2 gr of IMR 3031.

Anyhow, I would like to build a pistol AR with a 10.5" barrel. Would my load even work? The slowest 10.5" barrel twist I can find is 1:9.

My question is, if I shoot this load with a 1:8 twist in a 10.5" barrel, will I have any chance for accuracy? Looking for 1-2 MOA.

Thanks,
cpy911

I just traded for an Ohaus 22-050F design to use in my AR 16" with a 1:9 twist. From what I'm told it is very similar to the mold you are using from RCBS. Your load data will be very helpful to me as I start casting for the AR platform. I don't mean to jump your thread and unfortunately I cannot help with info about an AR pistol(apparently I live under a rock somewhere) as I'm not familiar with them. It was just nice to come across someone that has had positive results from AR casting. Thank you for posting this helpful information.

[3jimbo3]

I do wonder though,

do you lube or powder coat?

[howe0001]

Cpy911, are these PC and are you using GC's?

[Geezer in NH]

Fast twist is better than slow twist

[cpy911]

I am using WW and gas checks. Running at maybe 2200-2300 ish fps. Way fun and cheap. Still does a job on cans and bottles and rings steel nicely.

[AbitNutz]

I used to cast for my Ruger Mini 14 some years ago. I had read that you got the best success when the gas port happened to be fall in one of the grooves instead of on one of the lands. I lucked out and mine fell dead center in a groove. I had all the usual problems you might expect but the gas port clogging with lead wasn't one of them.

I used a Lyman .225 55gr FN-GC iron mold with straight linotype. I never did get the action to cycle without severe leading problems. I think it was too light a bullet. If I were doing it today I'd go with something heavier.