All chokes were based with shells before plastic wads were around. Other than protecting the bores from the new hard shot your gun probably has too much choke. .051 is a bit tighter than I've ever measured. Use to be that .030 was full, now with turkey chokes and such nonsense we have 35, 40 and 45. Your 81/2F and a 1 1/8 is a standard 3 dram load, or should give 1200fps.