I guess...I have one of the .22s to make it lighter on the .223s. I had a 9mm and it went because of our mini magazine policy here. If we could have used 30s or better I'd still be working it out. I don't want the 7.62 x 39 because I don't feel the need, a .45 or .40 would be excess of the same for me. A .30 carbine would be neat but has it's own problems. I think the .308s are a bit big for the design, just don't want one. I saw the versions in 12 ga, but the mag restrictions again...