03-27-2024, 08:20 PM
I tried a similar load in the 20" Faxon upper today. New Starline cases, F205AR primers, 27.5, 28.0, and 28.3gr Benchmark (newer lot) and 75gr VMax loaded to 2.105" for the Faxon's shorter than Howa throat. I didn't measure, but 27.5gr shot a group wider than tall, probably 3.5" for 5 shots at 300 yards. 28gr went 2-1/2" and 28.3 must have been 6" +. This upper was assemebled with a BCA side charge receiver, and no gas tube, so literally a straight pull bolt. The smallish lugs on the Grendel/ARC bolt are still the limiting load pressure factor.
These cases were only collet neck sized and deburred before loading, and I thought I was detecting a bit of inconsistency in neck tension while seating bullets. I'll run some of these through the FL sizer before loading more and see if groups tighten up a little.
These cases were only collet neck sized and deburred before loading, and I thought I was detecting a bit of inconsistency in neck tension while seating bullets. I'll run some of these through the FL sizer before loading more and see if groups tighten up a little.