It is imperative to the 300blk shooter to understand practically every .308 projo is designed to perform at .308 speeds.
Even in a 16" the 300 isn't moving that quick. A bullet with a low frag threshold is your only safe bet and the truth is theres almost none out there.
If I were you I'd look at blk specific bullets like the 110gr black tip Barnes, 135gr Sierra Varminter or 125gr TMK.
Expecting a .308 bullet to open at .300blk speeds is like expecting a .357 mag JHP to perform at .38 speeds, or a 124gr Gold Dot to perform at .380 speeds. It just doesn't really work like that.
The other issue is people don't understand how short barrels affect velocity. Yes 300 burns it's powder in 9" for SUBS but supers gain MV (to an extent) with bbl length just like every other round.
Velocity is good. It's what makes bullet do what they do.