I reload 300BLK, it isn't that expensive but finding appropriate powder is the hardest thing these days.
You can't just use random rifle powders, I use H110, LiL'gun, and A1680. There are a few others that will work but not many.
I love 300BLK and currently have 3 rifles chambered in it (2 non restricted). It's great for target shooting and close range deer hunting. Every store always has 30cal bullets and the 300BLK can shoot any weight bullet.
Both of my non restricted rifles are shooting the same 155gr A-max load sub moa.
I've always wanted a dedicated 22 upper but I wouldn't have one without a 300BLK upper first.