thunter, sorry to hijack your thread. But to your original question. I have tried 00 remington and federal in a light before without vent rib but mine was 30" full choke and did not pattern well. I find with my shotguns that have screw in choke that modified or at most IM usually patterns best at 40 yards.

I am not sure what choke your barrel is. Plenty of aftermarket barrels out there.