Hi everyone. Been a while since I last visited this site. I've got several old Winchesters and have managed to get good accuracy out of most of them but my latest addition is giving me some problems. It's an 1894 in 38-55 that was manufactured in 1899 (serial no. 66XXX). Good overall original condition. The bore is decent but is dark and has some minor pitting. My first attempt at shooting it was disappointing with all bullets tumbling. The bullets were Hunters Supply 260g FP (.379 diameter) over light charges of trail boss and unique. Putting some H4895 under them resulting in most bullets going straight but not with great accuracy (about a 3 inch group at 25 yards). At that point, I slugged the bore and found it to be .3800". Figured that the gun wanted some larger bullets so I got my hands on some Hunter Supply 260g FP (.381 diameter). According to my calipers they actually measured .3800. These bullets did show some improvement in accuracy with H4895 producing 1 1/2 inch groups at 25 yards when shot at about 1,000 fps. Problem is they can only be chambered with some serious effort to get the action closed. One round would not chamber at all. Seems that the chamber may not be large enough to handle the bullets the bore needs. I am using new Starline 2.125" brass. Any thoughts on what I should do to get the old girl to shoot. A different powder? Softer lead? Jacketed bullets? This is a new issue for me and any advise would be appreciated. Thanks.