OK, got to the range last weekend. This is a hunting bullet, but my results were not good enough to me accuracy-wise - these were some of the common groups at 50 yards from a very good rest:
Rest:
So to "proof" to myself that my setup was OK, instead of my Savage 308 with a scope setup on 20x, I tried my 45acp pistol carabine (suppressed, of course!) with a plain vanilla 1x Red Dot at the same target/distance of 50 yards. Save for the two shots in the red area, most were grouped in a close group - better than I achieved with the 308!:
I remember when I was trying the subsonic 308 rounds at 10x magnification I was getting smaller groups than these. This time, when I cleaned the rifle I noticed medium leading (which took a good number of patches/scrub to clean), so I am thinking that my bullet alloy (even though it is in the 20-ish hardness range after being water quenched), and a single coat of BLL (Ben's Liquid Lube) is not cutting it. So far all of my shooting has been with pistol cartridges and the 45-70 which hardly ever went past 1500fps, and a single light coat of BLL has been enough, so I feel I need to try better/different lube for this "close to 2000fps" loads.
So right now I am inclined to:
1) I don't (yet) have a lubrisizer, so desides BLL I also got White Label's Deluxe Liquid Xlox (45-45-10) on hand, so I can try two light coats of that next time.
2) Back off velocity-wise and start again with subsonic loads making sure I got no leading, before increasing power and watching groups at 50 yards.
Any other advice?