What is the twist, what powder are you using?
7.25" twist. Currently using H-1000, but I did try R-26.
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.
While I haven't stretched this one too far, I have no problem running a bunch of rounds between cleanings. I do shoot moly plated bullets, but don't have any problems keeping this one clean with my normal routine of Bore Tech Eliminator and a little JB every time. I have a Hawkeye borescope, so I know what works.
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)
I've had two or three 6-284's with 8 twists in the past, so I knew what I was getting into.
