The chokes needed for a good turkey gun are very different than those needed for a good goose gun. Did you have your gun reamed out? Watch what shells you are buying, I had a friend tell me about a great deal he found on 10 gauge steel shells, if he had taken the time to read the boxes he would have realised that he had bought 1 3/8 ounce loads, which were available in 12 gauge for 3$ less abox and the 10 gauge shells were low velocity 1100fps or so shells to boot.
I try to keep my shot close so no real need for a 10 on my end. That being said and H&R single might not be too bad for highly pressured late season turkeys.