I have tried several different powders over the years but have now locked into using Trail Boss exclusively now. It has proven to be capable, safe, stable and you can't screw it up. It is fluffy enough to fill the case and no fillers required. I have never opened up the flash holes either, discussed and decided not to after I got solid setup. I did a lot of testing with primers and found that the Large Pistol (CCI) produced the most suitable standards on velocity and accuracy over the rifle primers. Depending on the range and barrel twist I run Hornady and Sierra 170gr FP and 180gr RN out of my 1/10" mostly for 200yd and under target shooting. The 200gr Lapua Sub-Sonic and 208gr Hornady AMAX are running in 1/9" barrels out to 350yds. Once you have a solid load it is more fun than shooting a .22l, more accurate and better range. Enjoy and hope this helps.
The Trail Boss, Federal GM brass, Large Pistol primers is the basics, but figuring out which bullet works best for the rifle and application is all the fun.
I don't really have much on the 150gr bullets, the 170gr FP or 180gr RN would be honestly the lightest I would recommend. The starting point will vary as well due to the barrel length:
16" w/ 1/10", 170gr, 9.0gr Trailboss
16" w/ 1/10", 180gr, 10.0gr Trailboss
20" w/ 1/10", 170gr, 10.0gr Trailboss
20" w/ 1/10", 180gr, 11.0gr Trailboss
Now again, I recommend you shoot the first loads without the suppressor installed, shoot at 50yds to verify bullet stabilization, and if you have a chronograph check velocity for workups. Hope this helps, be careful and always verify the barrel is clear of all projectiles before firing follow up rounds.
Stacey Blankenship @ Accuracy International
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