John, I admit to an imprecise and arbitrary approach to scatterguns. First, do thy fit me; then, can I hit with them? If so, I keep them and go into my preconceptions of what chokes and shot sizes work best in those gauges. You are right about actual constriction varying withe same designated choke--I used to measure them.
Now, I generally stick to 1 1/4 0z of 6-4s in a 12; 1 0z of 6s generally in the 20; and, 3/4 7 1/2s in the 28. This isn't hard and fast but generally my approach in the uplands which fo me means pheasants mostly.
I've heard about "your" sevens in the 28. Are they in loaded ammo or a hand load proposition?
