immediate update. moments later. working the bolt "dry" after clean up gave a very easy bolt lift, w/ no indication that things were going to "degenerate" into a sticky bolt cycle. so, in other words, a.o.k. wished i thought of this weeks ago. but, better late than never. jjj. end immediate update.
i am old. i am a sucker for a project. and, i don't have much legitimate to do. so.--
i bought a complete receiver/8mm mauser model 38 combination from sarco, the only part missing a front sight blade on the barrel. but, not a complete rifle, as there was no bolt to be had from sarco. this was no hill for a climber, and i soon found a bolt from liberty tree collectors, but not w/ a bolt face compatible with the mauser cartridge. (that is another story. more on that, as it evolves, but, signs are encouraging. hint: repro steel carcano ammunition clips just don't cut it. period. end of story. get brass clips.)
i rough inletted the whole mess into a surplus 1903 springfield stock (of unknown origin or iteration) with the help of a dremel drum tool, and did a quick and dirty inlettlng job on the tang and receiver, enough to hold everything in place while i tried to figure out the depth for the bottom metal, crucial since that controls the feeding from the mannlicher style cartridge clips. basically, i just used little spacers cut from waxed cardboard milk cartons between the stock and the lower receiver, until the whole mess was tight when the receiver screws were tightened. (curiously, the rear screw holds tight, and the front one comes loose ... go figure.)
but, getting the damned bolt to cock without a great effort just eluded me. i tired sandpapers on this surface and that surface, oils, and running the bolt "dry," and i would get it passable only to have it start to progressively lock up just before full battery, and then when i could hardly move the bolt handle up at all. i had to use a long "bar" over the bolt handle to pry it up, ... , and, well, that is not good.
i tried to find a local source for some lapping oil or lapping compound, to apply to the cocking cams on the bolt and the cocking piece, and oddly enough, no one had any of the goop, and the prices on the net just pissed me off. i put a 1911 together from a 1911builders lower receiver and kit (they graciously sold me the hand driven "lathe" to cut the frame rails & instructions on cutting the rails, and instructions on lowering the deck on the receiver by 0.0016" of an inch, which i did completely by hand with files and the like.)
the final fitting of the slide to the rails was done with lapping oil, an oil with a very fine abrasive suspended in the oil. it's simply. you slop the oil on generously, move the slide as far as it will go without forcing it into a jam, and remove, and repeat, until you have a very tight and non-wobbly fit. it takes less time than you might imagine, even with all the repetition, but it make for a ridiculously tight and wobble free fit. custom, as it were.
so, i looked around the walla walla valley this morning, and none was to be had.
but, i did find some white lithium grease, and an idea struck me. i'll do some polishing with sandpaper and the white grease together, and what is left over is bound to have a bit of abrasive "washed off" the sandpaper. if i gather that part (easy to spot, as it is "dirty" w/ silica/alumina particles), and mix that with the grease, i have a homemade lapping compound.
now, the nice part about using the white grease is that you can apply it to opposing surfaces, and tell from the patterns in the grease where the metal is making contact, and where it ain't. slathering the grease into the bolt interior via sandpaper on a dowel, and apply it to the firing pin and the firing pin spring, i hoped to smooth things up inside the bolt. and, putting a couple of applications on the cocking cam surfaces, bolt & cocking piece, i was finally able to see where they were rubbing, and not rubbing.
previously the cocking effort went pretty predictably, right up until the last little movement of the bolt, just a bit from full cock. after the above process, in its initial stages, the reason was evident .... there was no contact between the cam surface at it upper portion on the bolt, and the cam surface on the last little bit of surface on the cocking piece. in short, no contact, no rearward movement of the cocking piece and firing pin, and no bolt "lift" left to accomplish this.
to make a long story short, i seem to have resolved this. the bolt lift easily all the way through the cocking arc, and the rifle cocks with a relative minimum of effort. my exposure to carcano's is limited, but from what i have seem of german commission rifle model 88's, and other carcano's, i have room for improvement, because the cocking effort on both the others is less than the cocking effort on my rifle. but, progress seems to lie immediately ahead, and since this is "national hangover day," i've got nothing else to so do.
but, enough palaver. back to work. and, for those of you working on "parts is parts" carcano's, just keep at it. some sort of solution to your problems should be there.
john jay @ 1.1.2021 (it would be more satisfying to type 1.1.2121, but i won't live that long. more's the pity.)
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