I would much prefer to risk the regular factory 3" load than one cut to give a homemade slug. Many years ago the American rifleman did do a test on this "Conversion" & amazingly found a lessened max pressure, due no doubt to loss of gas from the shortness of the remaining hull. They did not however reccommend it as an acceptable alternative to a slug. People have taken a cut section from a 16ga hull crimped on both ends with the charge inside as a homemade slug, but even this would not likely give a very deep penertration on a Buff. Read a letter to a hunting mag many years ago from a man from ahe Appalacian region of east TN, who used #5 shot for all of his hunting. for deer & black bear he opened the crimp, poured in bees-wak & re-closed. He referred to it as "Waxing a Buck". None of these of course would be pressure tested & could indeed prove destructive to the gun, particularly to the thin-wall choke.
Miller
