Hi guys, I am curious about twist rate. I just picked up my Mega stripped lower a couple days ago and I was set on building a AR pistol but now I am thinking maybe not. I am however thinking a pistol caliber carbine would be really cool or maybe just another AR15 variant idk. I see often posted 1/9,1/8,1/7.... I understand that different twist rates are better for different weight bullets or different cartridges can someone school me here. I am considering a 9mm carbine or just another AR15 variant? I already have a carbine length AR and a Long range AR. What do I need to know in general for either a 5.56 twist rate and 9mm twist rate. I know 9mm has a really limited range but I was thinking of losing my sub2000. I just don't like it as much as I thought I would, maybe I will warm up to it down the road. Thanks in advance for any help.