Yes 50 yards can be done pretty regularly with Hevi-Shot Dead Coyote T shot loads. I use a IMP/MOD choke with all of the different denser than lead loads that I use on coyotes.
Most of the denser than lead loads pattern very tight so I don't use my Dead Coyote choke or my full choke when shooting the denser than lead shot.
I prefer the Rem Wingmaster HD BB or the Federal Heavyweight #2 shot over the Dead Coyote T shot or the Rem HD Predator T shot because of the denser patterns.
The Winchester Xtended Range B shot waterfowl or B shot coyote loads are 12g/CC just like Hevi-Shot is and it is about $2.00 to $3.00 per shell cheaper.http://www.lg-outdoors.com/products.asp?cat=12560
Check out the above link for the shells listed below. They also have B shot coyote loads.
Winchester Extended Range High Density Waterfowl 12 Ga. 3" 1 3/8 oz #B 100 Rounds Ammunition Md: SWXR123B