Why do they do this comparison not using the same shot size?
MG
I showed that comparison just to show the difference between the two shot sizes.
With KPY you can select 16 shot types that are different densities, 25 sizes of shot and 16 different load weights and select the inches of gel penetration that you require. Kpy uses 20% gel so it is pretty tough to penetrate. You also select the shot speed at the muzzle and it gives you the pellet counts for the weight of the load and shot type uou enter.
All of the loads below are 1 oz loads and the gel penetration was set at 1.50". Look at the speeds the different shot types start out at, the yardage for the 1.50" of gel penetration, the amount of energy it took that shot type to get that penetration and the pellet count for 1 ounce.
Steel #7 shot at 1800 fps gets 1.50" of gel penetration at 16.7 yards, energy 2.23 lbs with about 417 pellets.
Bismuth #7 shot at 1300 fps gets 1.50" of gel penetration at 22.3 yards, energy 1.81 lbs with about 339 pellets.
Lead #7 shot at 1300 fps gets 1.50" of gel penetration at 35.8 yards, energy 1.57 lbs with about 294 pellets.
Hevi-Shot 12g/cc #7 shot at 1300 fps gets 1.50" of gel penetration at 43.4 yards, energy 1.46 lbs with about 244 pellets.
FHW 15g/cc #7 shot at 1250 fps gets 1.50" of gel penetration at 73.1 yards, energy 1.17 lbs with about 219 pellets.
TSS 18g/cc #7 shot at 1150 fps gets 1.50" of gel penetration at 102.9 yards, energy .98 lbs with about 182 pellets.