I have quite a few 12 gauges and have reloaded for years. Awhile back I picked up a 20 gauge and reloader and have been pretty busy with it. I would like to make some heavier 20 gauge loads. While using 00 buck with 12 gauge 3 pellets fit nicely per tier, 9 total for 2 3/4" shells and 12 total for 3" shells. This obviously isn't rocket science but I was wondering what is the largest shot that fits similarly regarding the 20 gauge. (3 pellets per tier). I linked a shot size index site below for reference. Any help would be appreciated.
http://www.shotgunworld.com/ammo_s082000.html
http://www.shotgunworld.com/ammo_s082000.html