A couple of months ago, I bought a 1929 MN 91/30, Tula, hex receiver, ex-dragoon(refurbished). By the way MSMLS, my serial number is only 16064 higher than what yours is. It also looks like you have a nice looking rifle there too! It also appears that they made a lot of rifles that year! After spending 2 or 3 days of cleaning the cosmoline off mine(most of this time spent on the barrel), my barrel was still in bad shape. I had build up inside my barrel, even after spending this much time on it that it went from my grooves to the lands(filled it up). A friend suggested that it might be cosmoline from someone else firing it and not cleaning it first. He suggested taking it to the range to fire it, heat up the barrel and clean it immediately afterward. Needless to say, the 147 grain bullets were all over the page at 50 yards, but I was able to get quite a bit of that crud out of the rifleing. I'm still trying to get the rest of it out and got most of it, but not all. The last time I went to the range, I shot 203 grain and it was quite a bit more accurate and actually got a bullet pattern instead of being all over the page. I also measured the total length of these bullets and there was as much as an 1/8th of an inch difference in length with this Brown Bear ammo, which would also affect accuracy. So far, I've used Hopppe's no. 9, Shooters Choice, brake fluid, Nitro Solvent and I'm slowly winning the battle with getting my bore clean. At least I can distinguish my lands now and the crud is down below them!! I've also had to use .35 caliber brass bore brushes to get down into the grooves as tight as possible to get this crud out. Maybe, I'm just being too picky from the Army teaching me to keep my barrel clean enough to use it as a drinking straw(so to speak)
, but I also have a 1944 Enfield, No4, Mk 1* Long Branch(sporterized when I bought it)that was almost the same way. The bore finally came clean after I fired it enough and kept cleaning it afterwards. Anyone know of any shortcuts to get this crud out once and for all? I do know that a lot of the accuracy depends on how clean the bore is and I got this .303 British within a 1 inch pattern from the bulls eye at 200 yards with iron sights!! Maybe I should have bought stock in the bore brush company before I bought this Nagant! LOL