What is the twist, what powder are you using?
How many rounds do you shoot before it requires cleaning? I played with a 6mm-264 and discovered the fouling built up very quickly causing changes in performance. It was an experiment with a rechambered 26" Remington takeoff 243 barrel. Realize a new Bartlein would work better......
I remember Ross Seyfried making a 6mm-264 and having an issue with a hard carbon like substance building up on the first barrel due to not cleaning it every dozen rounds or so. IIRC he had to throw away that first barrel.
Nothing like a fast 6mm. Currently have two 6mm-284s. One shoots the 105 Berger @ 3425 fps, 26" barrel Other a lightweight varminter shoots the 55 gr ballistic tip @ 4100 fps.
You have created a true velocity monster with incredible downrange performance! Almost a ton of energy at 500 yds with wind drift 8.1" at same distance in 10 mph crosswind! (4000 ft)
