IMO stick with steel. If other than steel,prepare for sticker shock.
If you want more range and/or a tighter pattern with less flyers,have the guns forcing cones relieved.
You could also try different sizes shot on a target board. Less pellets per shot,but bigger pellets just might give you the results that you are looking for.
When they first came out with that Hevi-Shot Dead Coyote load,I tried it for the called yotes that hung up at 60-70yds. They did not perform any better that my 12ga,3",#2 lead ammo that I used to use for high flying geese. --- SAWMAN