14.4 grain WW296 over 110 gr FMJ is what I have loaded for many years. I only get 2 loadings before I have to trim. You can only apply a light crimp since it head spaces on the rim ( hence you need to trim or the crimp/head space is all over the place ).
Primers: I have always used CCI 400 ( small Rifle), some use CCI #41 military primers. Some manuals recommend the small rifle magnum powder with WW296 but I have never had a problem even in cold weather.
One caution, make certain all primers are firmly seated ( no proud primers ) since the M1 Carbine has a floating firing pin.
I am currently playing with some 90 Gr XTPs over AA#9 but I am not not ready to share details. Its mainly for a carbine pistol. I have not tried it for function in the rifle yet.
Lifetime NRA Member