For my first 15 years of bird hunting, I used my Model 42 Winchester (bored "modified") in the early days when it was my only shotgun. I used 3" factory-loaded shells with #6's for pheasant & rabbits... and #7�'s for everything else.
For the majority of my 60+ years of bird-hunting, I mostly used my own 12 gauge reloads in a Belguim-made Browning Superpose (bored improved cylinder & modified)... a trap/skeet load consisting of 1-1/8th ounce, 3-dram equivalent of Red Dot powder together with #6's for pheasants (copper-plated #6's in Nebraska on annual pheasant hunts) or the same shot weight/dram equivalent of #7 (yes "7's", not 7�'s) for grouse, chukars and partridge. For quail, I used 1-1/8th ounce & a 3 dram equivalent of either 7�'s or 8's in a 12 gauge. The 3 dram equivalent of powder probably yielded a muzzle velocity about 1250 fps (I never chronographed it).
I occasionally used my 28 gauge reloads in my Charles Daly over/under 28 gauge skeet gun (bored "skeet & skeet") with Herco powder and a variety of shot-weights... 3/4 oz skeet reloads... or factory loads of 7/8's or 1 ounce of shot... #6's for pheasants and usually #7� for chukars & partridge... and #8's for quail.
I never hunted the 28 gauge skeet gun without a good dog due to the very limited range (20 to 25 yards at most) of the skeet chokes.
The advantage we reloaders have is that we can choose any combination of shot size, shot weight and powder choice plus the amount of powder used to give us the most effective shotshell load possible for the game hunted and the expected type of cover.
I've always preferred AA hulls, but there's a lot of good hulls these days. For the 12 gauge, I'd recommend the 1-1/8th ounce load which I've always found gave excellent patterns. Since I never owned a 20 gauge gun, I can't suggest a load for it.
Strength & Honor...
Ron T.
