Your reloads with good shot like Lawrence or West Coast stand a better chance at the pattern plate than the commercially loaded 'heavy field load' stuff.

This is why the 1 oz. 20 gets a bad reputation. They run soft shot too fast and are shocked that it won't shoot tighter than IC.

Truth be known, that's adequate for most.

But... if you want an honest modified or full choke pattern from the 1 ounce 20, you're best served with a slow-ish load of hard shot.

But you know that.... and it plays right to your desired velocity/mass combo for regulation.

Longshot and either the RXP-20 or the SP-20 at 1100-something and you're probably where you want to be.

"The price of good shotgunnery is constant practice" - Fred Kimble