Last year at the Western Games, I participated in the M1 Carbine match. Shooting Remington green and white box fmj at 100 yards the rifle was shooting very low. My solution was to set the sight on 300 (adjustable sight) and hold top of black on the SR-1. Shot a middling 303/400 (forgot during rapid sitting to hold top of black :-(.
Anyway it inspired me to get it shooting closer to the sights. I whipped up a batch of Hornaday 100 grain SJ with 15.4 grains WW296 and 311359 @ 309" with 13.5 grains WW296, both with CCI 400's. Interesting results. The heavier cast going slower shoots higher than the lighter half jacketed bullet. I guess in revolvers, that is usually the case, did not expect it in the carbine. Shooting off the bench at 25 yards all groups looked very nice, but at 100 things of course open up. My best groups were four inches with the half jacketed load, sight on 300 and a fat line of white (not a very precise sight picture). The carbine is set up properly: nothing is loose, the action hangs off the recoil lug, it has a bayonet band and pot belly M2 stock, with a good crown and muzzle. Definitely need more groups before I start messing with filing the front sight.
One slight issue that gives me pause was with the 311359 twice in 15 rounds the empty gets about 2/3's out of the chamber and then traps the next round in line. Every other case, and all of the half jacketed (and RP factory) are flung over my head and 10' behind me. The cases looked fine so I'm at a loss as to what happened. I weighed all of the charges, but there might have been a couple of rounds that had slightly different seating feel, maybe not as tight as the rest, but not fall out of the case loose either.
Any thoughts on shooting low and the odd extraction of two cases are welcomed.
Enjoy your Holiday.