I'd look at a slower powder than Bm2, I use 41gn Re17, 123amax, CCI BR4 primers, start at 39gn & work up. (24" barrel rifle)
I got very good accuracy also with 2208 & 123amax, start at 36gn, I hit the sweet spot at 38.4gn, both of these are warmish loads, Re17 gave me more speed so went with that, the CCI450 Magnum primers are generally the go to for this calibre but I found the CCI BR4 primers gave me a bit more speed in my 24"barrel rifle. (+25fps)
In my 19.5" rifle the CCI450 & Re15 did the business (123amax, 38.6gn Re15, CCI450)
Others loads I played with,
140Amax, 40gn Re17
120 Pro Hunters, 42gn Re17
Good luck, it's a great calibre.
Bookmarks