The limiting factors on any shotgunning is the point at which you can no longer either hold a close enough pattern to ensure a hit, or no longer have adequate penertration. Generally speaking the denser the mat'l of which the shot is made the further from the gun these factors can be met. When No-Tox first became mandatory for waterfowl Steel was the only other game in town. Advise very quickly materialized for success to "UP" your shot size by two from what you had been using in lead, IE if you had been shooting over decoys with #6 go to #4 etc. Even then the lead was slightly superior. I have not kept up with HS, but when it made its debut it was noted as being heavier (Denser) than lead. It was suggested one could drop a size with it over lead.
To simply compare various shot of differing matl's only by Diameter doesn't paint a true picture. If you want to get the most #6's you can get in 1 3/4oz then shoot aluminum shot, just don't expect to Slay very many 60yd Toms with it.
I am not a dedicated Turkey hunter & for the few I have killed lead has served me well, but I would not with my current equipment (12ga 2 3/4") take a shot I thought was beyond 40yds & would really prefer it inside 35.
