Tim (Flyer01)...
The "secret" to getting a RSI to shoot smallish sized groups is PATIENCE and allowing the short, light 20-inch barrel to cool down to "just barely warm" between shots... 'most likely due to all the wood surrounding the barrel.
If I shoot three shots in-a-row through my #1 RSI in 7x57mm... the 3-shot group is well over 1 inch in diameter.
However, if I shoot one shot, then lower the breech-block and allow the rifle's barrel to cool down to "barely warm", then take the next shot and repeat allowing the barrel to cool down, the sweet little rifle has shot several 3-shot groups off the "bench" measuring .176 inches to .179 inches @ 50 yards with the 4-12x40 A/O scope set on 12x and the adjustable objective turret set to 50 yards to eliminate parallax.
The "sweet spot" load to get those smallish-sized groups ranged from 47.2 grains of H4350 (3 rounds = .176 inches @ 50 yards) to 47.6 grains of H4350 (3-shot group = .179 inches @ 50 yards). The maximum "book" load given was 50.0 grains of H4350 which yielded a 3-shot group measuring .407-inches @ 50 yards off the bench with an approximately muzzle velocity of 2800 fps (didn't take my chronograph to the range that day) with a 140 grain Sierra flat-based ProHunter soft-point bullet and standard Winchester large rifle primers in "accurized" Winchester cartridge cases.
With THAT load, the little rifle didn't "bark", it "bellowed"... and recoil was "noticeable", but not harsh. This load would be a good hunting load for even the largest deer with the 140 grain Sierra ProHunter bullet, but I'd use 140 or 150 grain Nosler Partition Spitzer Bullet for elk or moose and place my shot carefully and accurately.
I measure the outer-most edges of a group, outside-edge-to-outside-edge, with my digital calipers and subtract the diameter of the bullet (.284") to determine the final, actual group size. This is, to me, "THE" most accurate way to measure a 3-shot group.
Strength & Honor...
Ron T.
