Some of the 338ME and 308ME guns had "barrel droop". The equipement/machinist was not aligned correcly and the receivers were threaded so that the barrel pointed downward. You can check by running a straight edge across the top of the receiver and comparing against the bore.
Marlinowners.com should have some articles on it as well
Guns that were repaired will have "JM" stamped barrel but "RM" serial numers as they replaced the recievers
Last edited by WStrayer; 08/04/21.
