Great choice!! Nothing wrong with the M1 at all, I have one. It IS the Cadillac of Shotguns. You did very well for your first scattergun. Just make sure you feed it good ammo. Something with a high dram equivilent, (higher power). Don't hang a bunch of accessories on it either. The extra weight affects the cycling which may cause loading failures. You may want to 'break it in' (if new) with a few cases of 3
" magnum rounds. Oh and if you do get some Ben Gay for your shoulder My first was a Winchester pump, pictured below. Smoothest pump I ever racked. Here's my M1.
Mike