I'd say you have slight metal burr somewhere close to where the bullets catch. I use Ranchdog 265s and 350s which have about a 72% meplat for my T-4. I have to seat my 265s at 2.492" OAL, and my 350s at 2.524"OAL for smooth cycling. I use a piece of brass cut like the one in the picture to find my OAL. I put a bullet in a dummy cartridge, (no primer no powder for those new to reloading), and slowly close the lever in my gun to get an almost tight fit. Then I back off no more than .020" as a start for seating. I note that my gun seems to require much deeper seating for the 265s than many people talk about. This just indicates that each gun is different, and you have to find a way to make it work within limits acceptable to you. Since my bullets are seated deeper, I use less powder to adjust for pressure than many people do. Another cost saving factor that works in my favor.
I rarely shoot paper because of lack of interest, so I can't speak about target groupings resulting from my techniques. I regularly shoot all kinds of reactive targets like jugs or buckets or spray paint cans with much satisfaction. YMMV.