I have a topper 88 , and on a lark fired some older Remington 12 GA shurshot 5# at a turkey pattern at 40 yards it patterns great . the load is what Remington calls high base pheasant load 3-1/4 -1 -1/4 #5 -1220 fps The topper has full choke not much recoil . I know 20 GA high brass 1 oz load of #6 is 1220 fps.

thanks Iver