Full disclosure: 300BLK is
not my favorite
game round, but is probably my favorite round to shoot; I shoot more 300BLK than all my other rifle calibers combined. I just love how easy it is to tune if you reload, and how incredibly versatile it is; albeit, within a pretty small performance envelope.
Great round as long as you don’t try to make it something it’s not.
All my 300BLK are gas guns, and I have uppers ranging from 8” up to 16”. 300BLK is designed to burn completely in ~8” of barrel, but I’ve seen and shot them as short as 6”. I only shoot suppressed.
300BLK works great for shots inside 150 yards or so; really within 100 or so for supers, but I won’t take subsonic shots on game at more than 50 yards or so. Again, they work fine inside their respective envelopes, but there's not a lot of energy out past 100 yards or so, and the subsonic rounds in particular basically have the ballistics of a thrown rock. LoL
Speaking of that, I generally zero my 300BLK uppers at 50 yards; exception being the two used almost exclusively for hunting with supers. They both have scopes and are zeroed at 100 yds.
My favorite do everything 300BLK load is the 110gr Barnes flat base black tips over 19-20 grains of H110 powder. Really nice for hunting, and good performance within 100-150 yards. The Hornady 110s seem to do just as well as the Barnes bullets, and are a lot easier to find.
I prefer to use Accurate 1680 powder for my subs, but the H110 seems to work just fine for subs too. I usually load 220gr Sierra HPBTs over 9-10 grains of powder since I use 300 subs almost exclusively for just punching holes in paper, but I have recently been using the 190gr Hornady sub-x bullets. Haven’t shot any game with that bullet though, so can’t speak to its effectiveness for hunting.
I probably need to do that soon though since our primary HD rifles are chambered in 300BLK, and loaded with those 190gr subs (factory ammo in those).
Remember, the 300BLK was originally designed to provide better effects on target than a 9mm PCCs (specifically MP5s) at ‘across the room’ distances, using subsonic bullets. It also proved very effective with lighter-weight supersonic ammo though, and basically became the AR version of the 7.62x39 AK round.
Just my $0.02
Edit: a few of our 300 BLK rifles/uppers:
16” that we loan out a lot…good all around plinker and hunting rifle:
My personal favorite for hunting though is this 10” barrel, and has the old Leupy Mk5 scope with the 300BLK reticle:
My son and daughter each have a 10.5” 300BLK upper for their SBR’d ARs:
…finally got the red dot shroud Cerakoted pink too, LoL:
My go-to HD and truck gun when travelling; 9” barrel:
And an 8” done as a pistol; got tired of having to notify the bureaucracy if I wanted to cross state lines with one of our SBR’d lowers.
…that upper gets shot enough that it has an actual red dot and magnifier now:
