seems like for every gram per cc you gain the performance of the shell increases dramatically.
I think hevi-13's and the hevishot Nitro's are around 12g/cc
Nitro Megaweights are a little over 13g/cc
Federal Heavyweight is 15g/cc.....It is awesome for a factory shell if you can get your gun to shoot it
TSS is all the way up there at 18g/cc. The way Hal explained it to me is that a #9 TSS pellet has the same lethal energy as a #4 lead pellet or a #5 hevishot.
What really blew my mind is when he told me that a 7/8 oz dove load of #9 TSS would have about the same firepower as the 2 1/4 oz 3 1/2" Hevi 13 5's that I used to shoot.