RE: Good turkey choke for Mossberg 500?
How much do you want to spend? You can get the cheaper stuff for $10-$15 a box stuff or you can get the latest and greatest stuff that's $40 per box. All of these boxes have 10 shells in them, not 25 as is with a regular box of shotshells. I killed my first bird with a box of 3"Winchester Supreme#6's. The "cheap" stuff". There's nothing fancy about those except that they kill birds!
Having said that, I believe there's a trend leaning toward the "heavier than lead" shells, ei: Hevi-Shot. I've shot this stuff for geese and in my opinion, it's the best thing going. I'll definitely be shooting this stuff at turkeys this spring. It's probably best if you take baby steps right now though. Stick with lead for now, get yourself a good pattern and have fun!