I recently got a set of 20 gauge Briley Untra-light tubes for my 12 gauge O/U. My first outing resulted in several fail to ejects on the upper bbl only. Ammo was Rio #7.5 at 1250 fps, high brass. Don't know if it is a weak ejector spring, burr on the Briley ejector, or whether the Rio's are the problem. I did later take the Briley ejectors out and de-burred them a bit. Any guidelines for ammo with 20 gauge tubes? Thanks!