Edge -- Here's some info I've posted before on 20-gauge pheasant loads.
If choked appropriately, 20-gauge 1- to 1 1/4-ounce loads of lead #6s or #5s should take care of any pheasant shooting out to about 40 yards. Here are a few of my pattern numbers from loads I've shot pheasants with to give you an idea of how a couple of my reloads perform, in my gun anyway!
Patterns from a 20-gauge Browning Citori with 28" Invector-plus barrels and Briley flush chokes (patterns average of five, 30" post-shot scribed circle, yardage taped muzzle to target, and in-shell pellet count average of five).
20 GA 2 3/4" RELOAD (BLUE DOT)
1 oz #6 lead (233 pellets) 1200 fps
30 YARDS – SK / pattern 147 (63%)
30 YARDS – IC / pattern 168 (72%)
40 YARDS – M / pattern 146 (63%)
40 YARDS – IM / pattern 163 (70%)
20 GA 3" RELOAD (BLUE DOT)
1 1/8 oz #5 lead (190 pellets) 1220 fps
30 YARDS – SK / pattern 140 (74%)
30 YARDS – IC / pattern 149 (78%)
40 YARDS – M / pattern 138 (73%)
40 YARDS – IM / pattern 147 (77%)
Some public lands require nontoxic shot, so if you need nontoxic go with 20-gauge 3-inch 1-ounce loads of either #3 or #2 steel. Steel shot lethality research on pheasants conducted by Tom Roster showed #2 steel to be more effective (at all ranges) than either #6 or #4 steel. Yes, you can kill pheasants with #4 or #6 steel loads, but a little extra pellet energy is a good thing on wild pheasants where shots tend to be going-away and can get on the long side. The research also showed #2 steel resulted in fewer cripples than both #6 and #4 steel; and Roster also speculated that the #3 steel pellet would be a good compromise between pellet count and downrange energy.
Here are a few of my pattern numbers to give you an idea of how these loads perform, in my gun anyway!
Pattern numbers from a 20-gauge Browning Citori with 28" Invector-plus barrels and Briley flush chokes (patterns average of five, 30" post-shot scribed circle, yardage taped muzzle to target, and in-shell pellet count average of five).
20 GA 3" WINCHESTER DRYLOK SUPER-X STEEL LOAD
1 oz #3 steel (145 pellets) @ 1330 fps
30 YARDS -- SK / pattern 114 (78%)
30 YARDS -- IC / pattern 123 (85%)
40 YARDS -- IM / pattern 106 (73%)
40 YARDS -- LF / pattern 110 (76%)
20 GA 3" REMINGTON NITRO-STEEL MAGNUM LOAD
1 oz #2 steel (118 pellets) @ 1330 fps
30 YARDS -- SK / pattern 101 (86%)
30 YARDS -- IC / pattern 105 (89%)
40 YARDS -- IM / pattern 99 (84%)
40 YARDS -- LF / pattern 102 (86%)
Good luck!