If i can post pictures anyway. we'll see...
Anyhow, i am still on my heavy shotgun load kick (no pun intended); and decided to see what the 'secret' was, if any, that Nitro Ammunition Co uses to cram 2.25oz into their lead buckshot loads.
I disassembled load B301 (Buckshot load [bottom of webpage], 3" 2&1/4 oz No4Buckshot).
First pic is the shell, w purple and green plasti-dip-type sealant on the crimp. The stuff was dry, malleable, but not so hard as to be needed to reinforce the crimp.