I'm taking my LC Smith out turkey hunting this year. If you are buying commercial loads, then RST is the source. If you reload, there are many loads compatible with your elsie. I patterned 5 different loads this morning looking for the best mix of velocity, charge, and pattern. My 12 gauge has full/full chokes and is red hot with 1-1/8 oz out to 45 yards, and is still effective on my turkey target at 55 yards. I get my best patterns below 1200 fps which is still mighty potent at 50 yards with #4 shot. FWIW, I don't think I've ever shot a turkey past 30 yards anyway. I like to let them get close enough to keep shot out of the meat and avoid hitting any other birds.
Rob.