Look at the wood on that Ruger...
GCF...A question or two or comments if you do not mind.
Looking at your targets my attention was drawn to COL. Target #1 shows COL 2.985" with Sierra 140gr SP which is just shy of Sierras suggested COL of 3.000" Target #2 shows COL 3.070" with Nosler 140gr BT.
Are you seating out the bullets just shy of the lands or are you backing away to a specific sweet spot?
My M77 magazine length is 3.390" so I seat bullet to obtain COL less than that...for example 140gr Sierra SP COL is 3.120" and 154gr Hornady SP Interlock COL is 3.280".
My M77 TS 7x57 is a pre-1985 with a 1:9 1/2" ROT and has a propensity for 140gr and lighter bullets. A couple of amigos in the gun club have post-1985 M77 7x57s with 1:8 3/4" ROTs and they tend to shoot the 150 - 160gr bullets well although my pre-1985 does a respectable job.
