Short barrel 300-221

[RWBlue]

I am looking to do a SBR AR-15 project in 300-221. A very short 10-12 inch barrel appears to be best for my project, but I don't know the balistics for 300-221 with a short barrel.

How short of barrel is too short?

[gt3499a]

mine is 11.5" and seems to be about right. I wouldnt want to put the suppressor any further forward than that for ballancing purposes.

8" is the shortest that I know of with a 4" gas port possition.

makes me wonder if I could make up a blow back 300 whisper with a 4" barrel. Would have to fix the bolt to prevent rotation and attach weight like a 9mm carrier. It would then be unable to handle supersonic loads. My standard load is 8gr of h110 with a 180gr flat based bullet. Wouldnt get as much gas in the face that way. Might have to bake this theory a while longer.

good luck