Originally Posted By: pyscodogMy rifle is a 6AI. I'm just starting load work. First powder used was H4350 and results weren't to good. I'm going with R-19 on my next range trip and if it doesn't work I'll try 4064 or Varget.Best I can tell, mines a 12 twist and has a really long throat so touching the lands is near impossible. Giving me fits with the long jump.
Bill, the 85g Sierra bthp are somewhat forgiving in bullet jump, I have jumped them up to .092 with good success. My load was 44.5g of R#19 with a win primer, back off a tad and work up in two shot increments. I shot the same load with the 85t Barnes tsx with great results because they need some jump. Best accuracy will be right close to the red line in pressure....mid level to upper mid level pressures will not be accurate at all. Edges of primers were flat at the accuracy node. 85g Sierra was doing 3550 with good accuracy if you want to put up a chronograph while you load develop.
In two 6/284's I shot the same Sierra 85g bthp at 3600 with a heavy dose of IMR 4831 which was close in burning rate to R#19.
Primer choice makes one heck of a difference on grouping.
In a zero freebore chamber, 14T shilen, I shot the 80g Sierra bt Blitz at 3800 with R#19 and win primer, win brass. In the same barrel, I shot the 70g Nosler at 4100-4150 with Win 760. In a 10T Douglas ss match, I shot the 70's at 3980 fps. The 6 AI rocks along with the 6/284 with short to zero freebore and slow twist barrels.
