I've been on a quest for the most accurate load for my Ruger #1 International (aka "RSI") in 7x57mm with the Mannlicher-style stock and 20-inch barrel... and am in the process of trying 5 different powders, 6 different primers and 5 different bullets in varying combinations in the rifle.
I did shoot a MAXIMUM load meant for MODERN 7x57s ONLY... (not the old 1893 and 1895 Mausers)... which is 50.0 grains of H4350 behind a 140 grain Sierra, flat-based ProHunter bullet. It
DEFINITELY had a louder report (than any other round) and a pretty good "shove" compared to every lighter load I've ever fired in the rifle.
However, even though it was a MAXIMUM load, the recoil and noise was NOT objectionable... just louder than lighter loads which is to be expected.
Generally, with the RSI's shorter, lighter barrel, you can expect about a 50 fps to 80 fps drop in muzzle velocity, but even with the shorter barrel, one can achieve almost 2800 fps with a maximum load of H4350 powder.
Incidentally, accuracy was very good using H4350 rifle powder throughout the entire range of use. At maximum charge (50.0 grains behind a 140 grain bullet sparked by a standard Winchester large rifle primer in "accurized" Remington brass), the little rifle was still giving me .404 inch, 3-shot groups @ 50 yards.
I hope this information helps you...
Strength & Honor...
Ron T.