On my 835 I use a comp n choke xxxfull chocke on a 24" barrell, I'm shooting 3 1/2 Win HV#6. At 40 yard I get 8 -12 in kill zone. It's top off with a Bushnell Trophy red dot with a Sim Limb Saver recoil pad. Shot my frist turkey with this set up last spring at a little under 20 yards lets just say it was devastating I now know were the term jelly head comes from.