I have shot a few of the 65gr. Sierra Gamekings out of my 16" Bushmaster M4 ORC 1 in 9" Twist. I am loading them with H-4895 (don't have the powder charge or velocity in front of me right now). My accuracy has been 1" to 1 1/2" for 5 shots at 100 yards from the bench.
I loaded these up for my wife to use for Whitetail Deer. Unfortunately she never did get a shot this year. I did test them on Gallon Plastic Milk Jugs full of water. I stacked 4 jugs one behind the other. I found the jacket in the 4th jug with the lead core exiting the 4th jug.
My accuracy has been 1" to 1 1/2" for 5 shots at 100 yards from the bench.
Sorry I couldn't be more help.