What I have found to work best was a choke with a ED in the Imp Mod range(That's inbetween Mod and Full). I've tested Rem 00, Win 00, Win #4, Fed 000, and Fed #1. Fed Premium #1 gave the best kill counts to 75yds with an IM choke. A good quality after market extended choke will work well. From a Rem or Win bore something in the Neighborhood of .715 ED should do well.
Primos, Kicks, and Pure Gold make extended Buckshot chokes.
I pattern alot of shotguns and just like rifles, they will tend to have a pet combo. Try a few combos and see what gives you the best patterns. Look at your overall pattern on large 3'x3' sheets of paper. Ideally you will want an even pattern with no large gaps that gives a dense 20" core. Also make sure your gun is hitting POA. Some folks think a shotgun naturally shoots to the POA with the factory bead, but that's far from the truth with many guns. You can buy 35" wide 140' long rolls of paper for $10 at Home Depot in the paint section. Large paper is very important in studying patterns.
My most rescent buckshot test were with an Mossberg 835. The key combo was a IM ext choke and Federal Premium 3.5" #1 buck. That combo gave excellent patterns and I wouldn't be afraid to use it on small deer out to 70-75yds in calm conditions.
Good Luck
loder
