strut,i shoot 3.5x4s hevishot using a rem xfull and a stardot and both pattern out to 60 yds.i am having a 28" barrel on a browning 500g cut down to 22"and carlson's chokes is installing a .670 truchoke on the barrel.they say that the .670 is best for #4 shot.i have seen the rhino chokes in cabellas and redhead catalogs.