This may sound silly but if you have and spent hulls of the rounds that jam try trimming them to length lof the live shell. I fixed a guys blackace Shitgun seeing that technique. That gun will still not cycle soft hulled shells
I heard on a ammo form that a couple of ammo companys are working on ammo for pistol caliber carbines.
I'm guessing higher pressure longer/ slower burning powder to squeeze out as much speed as you can out of the longer barrel but slow enough burn that you wouldn't over pressure a pistol but the...
You don't hear much about or from the Sandyhook family anymore since the truth came out.
Sad part is your not hearing about Texas anymore either where is Hogg he's not the only adult in the room anymore.
Don't forget the 6.5 Grendel.its a sweet soft shooting round and has been known to take deer out to 300yrs.
You can build a 6.5 Grendel upper for you AR15. It's a great round.
I have a 6.5 CM as well awsome round and if you reload you will have a gun that will out shoot you .