I know they operate on inertia as the Bennelli does. I had a Super 90 14" entry that wouldn't cycle with low brass, much less the Winchester reduced recoil loads. I would bet some full power high brass would fix the cycling issue. Also, I purchased some Sellier and Bellot (sp?) high brass buck shot which wouldn't cycle in my Super 90. After staring at the rounds, I noticed that they were about 1/4" longer than anything else. The hulls were not crimped, but the shot was secured with a plastic "plug". Just a thought.
"People live too long, dogs don't live long enough" - FTF Member-