The issue that causes the 'Marlin jam' is a timing issue with the carrier, so almost any of the marlins can be affected. I've a 444 doing it now. The 1894's are not any more prone than the others but they get used a lot in the 'cowboy Action Shooting' game and thus a lot more rounds expended... To check the problem, remove the lever screw and the lever. The cam surface on the bottom of the carrier will have a fairly obvious line 'peened' across it by the nose of the lever cam.. The 336's with this problem are usually pretty old before it developes and most of the time a new carrier is installed.. I've even installed a couple myself. I don't like bending the carrier as a fix.. but have found that welding a bead on the carrier face (top) with a MIG and dressing down to a few thousandths higher works well and I've and excellant welder available..