Absolutely- I use a Browning BSS in 20 ga. and have used several O/U's. Heaviest loads are 1 1/4 oz. #6's, but one ounce, 1 1/16 or 1 1/8 will do near as well if you don't try to make a magnum 12 out of a 20. I was able to get some nickel plated 5 1/2 shot from BPI and in reloads that stuff absolutely flattens roosters. I hunt over a dog and shots are sometimes a bit closer than wild North Dakota birds but the shot is what does the work, and the pheasants don't know what gauge fired it. If you are stuck with non-toxic loads though... I move to the 12 for better selection (and economy...) of loads.
