Was checking out the functioning on my 22" barrel 1895 and discovered that loading cartridges into the 4 shot magazine had become nearly impossible. The gun is essentially new.
When I bought it though it seemed to only require reasonable finger pressure. More finger pressure than a .30-30, .357 Mag, .44 Mag, or a .45 Colt, but not horrible.
So I removed the fore end and magazine tube for inspection.
Unlike other Marlin magazine tubes this one had a deliberately formed large bulge to facilitate navigating the long fat .45-70 rounds through the loading gate. Internally, the tube looked dirty near the loading gate end, but the tube end was free of burrs or sharp edges.
I scrubbed the tube with a .45 caliber brush wrapped with 0000 steel wool and bore cleaner, being sure to clean out the inside of the bulge. I also went over the exterior with steel wool, which seemed coated with preservative. I finished by cleaning up with bore cleaner and patches and then lightly oiled it. Then I reinstalled everything.
Problem solved. One thing I noticed was that the tube follower was made of a pretty thick and wear resistant hard plastic. I doubt that these need to be replaced by aftermarket metal ones.
Whatever the coating is inside these tubes, it causes a lot of friction if it dries out.