The above pattern was shot at 40 yards and it was a Remington Wingmaster HD #2 shot 1-1/2 oz load.
This pattern was a Federal Premium 3" 1-7/8 oz copper coated BB load with 98 pellets in it. 15 pellets hit in the 12" circle.
This pattern was shot with a Remington Wingmaster HD BB load with 70 to 72 pellets in it and it had 32 pellets inside the 12" circle. Notice how the HD BB load with about 25 less pellets in it put over twice as many pellets in the 12" circle than the copper coated lead BB load did.
I have to shoot lead free shot at coyotes and the Remington HD BB, the HW13 BB and the Federal Heavyweight #2 shot are my favorite shot sizes. The Federal Heavyweight #2 shot has 90 pellets per 1-1/2 oz load.
Below are some speed and gel penetration numbers fro the KPY Shotshell Ballistic program using different types of shot. This program suggests that 2.50" of gel penetration is required to reliably kill geese. After entering a bunch of numbers with lead BB shot it looks like 3.70" of gel penetration would be close to what is needed to reliably kill coyotes.
I do not recommend using steel shot for coyotes and just because a lead number 4 buckshot pellet can kill a coyote a long ways off doesn't mean you should be shooting at coyotes a long ways off with lead number 4 buckshot.
Steel T shot at 1500 fps gets 3.70" of gel penetration at 23.4 yards.
Nickel plated lead BB shot at 1300 fps gets 3.70" of gel penetration at 47.6 yards.
Remington Wingmaster HD BB shot at 1300 fps gets 3.70" of gel penetration at 64.4 yards.
Federal Heavyweight #2 shot at 1300 fps gets 3.70" of gel penetration at 72.8 yards.
Lead #4 buckshot at 1250 fps gets 3.70" of gel penetration at 109 yards.
Federal Heavyweight Coyote BB shot at 1300 fps gets 3.70" of gel penetration at 119.4 yards.
The tungsten alloy denser than lead shot is much harder than lead so it patterns really good, it penetrates deeper and breaks bones much easier than lead shot does.
If you ever come across some Federal Heavyweight #2 shot waterfowl loads at a decent price buy them!