I put about 80 through it today with no feeding problems, but still had a few FTE at 4.3 and 4.5 of Bullseye. Anything more than that and my groups turn into buckshot patterns.
The extra power spring seems to have helped but I'm now thinking the extractor is the culprit. On top of that one of my mags has a split at the back of the feed lips. Sheesh.