Waldo –
My .257 Roberts is a 22” Ruger made in 1989. As do several of my Rugers, it has a long throat which, like the long-throated Weatherby chambers, allows greater velocity. I run Winchester +P brass for the following loads:
3609fps = 75g V-MAX, H4895
3252fps = 100g TTSX, H4350
3162fps = 110g AccuBond, H4350
3013fps = 115g TSX, H4350
2947fps = 120g A-Frame, H4831SC
2904fps = 120g Partition, H4831SC
2899fps = 120g Grand Slam, H4831SC
Accuracy with the Partition and Grand Slam are OK for hunting out to 300 yards or better, accuracy with everything else is excellent.
Recoil is mild with all of these loads. When deer and elk hunting in combined season I use the 120g A-Frame load.
The Roberts has become my favorite shooter and clay pigeons on the 400 yard berm don’t stick around long. The 75g V-MAX have accounted for two coyotes in the 480-490 yard range, both first-round hits.