BSA, that's good shooting & a very nice rifle, but that load of 20.5 gr of AR-Comp is only around 23-2400 FPS................for reference Black Hills MK 262 is nominally 2750.
I've been using AR-Comp for a while & am generally around 22.4 - 22.8 gr with 77 gr bullets for 2700 -2750'sh in multiple guns.
C'mon, man, ya gotta get with some Big Boy loads for that new rifle.
Here's a link to one of a series of trials done to attempt to duplicate MK 262 loads with various powders.................about 10-12 episodes altogether. He shows 22.0 gr AR-Comp as being around 2625 FPS & you are 2 full grains below that.
For the last year or so, I've moved to IMR-8208XB as my prime go-to powder for an AR for the most part, but I'm going to try some AA-2520 in the near future too.
