Junior's sight project on his M44 about a year ago really piqued my curiousoty as to the feasibility of mounting some decent sights on a Mosin. I like the Mosins because they're inexpensive and lend themselves well to cast bullet shooting, but I really dislike their sights. I also like the idea of this kind of rifle for knocking around here on my place as if it gets banged around on the tractor, it's no big deal. I decided there had to be a way to mount some better sights.
I bought a clunker M44 with a nice barrel and first modified the trigger (posted about it here: 2¢ No Creep Adjustable Mosin Trigger) then I began in earnest looking for a way to mount a receiver sight and a Patridge or blade type fron sight.
I discovered that an M1 Carbine front sight base/sight would fit perfectly on my barrel, but it would be much too short. I really like the front sights on the Finnish M39's, so I decided to modify the existing bayo lug/front sight base to accept this type sight. I first hacksawed off the bayo lugs, then ground the remaining metal as well as the dovetail slot down as best I could on a bench grinder. A few years ago, my Dad dumped an ancient Atlas lathe off at my place and I set it up and began tinkering with it. I was able to turn the original sight base and lug down sufficiently to a collar or bushing and mount a Finnish fron sight:
I'll probably go back and turn this collar down a bit more so that the rear of it will be the same diameter as the barrel where they meet.
Next was to tackle the rear sight. The obvious hurdles are the split receiver and the straight bolt handle. First, I figured out a way to mount a really low bolt handle that would slide under the arm of the receiver sight. I made a butterknife type handle out of 3/16" plate steel because I needed a bolt handle that was flat where it attached to the bolt body. Next, I sawed the original bolt handle off the body, filed a flat area where the handle had been, then ground and filed a recess for the butterknife handle to sit in. I tinned both pieces and silver soldered it in place. Please excuse the rough metal. This was an experiment and as such, I've not yet done any finish polishing.
The next problem was that the bolt handle wouldn't clear the top of the receiver behind it, so a little judicious work with a file was in order. I lowered this portion of the receiver probably 1/4" - 5/16". That solved the problem.
Next was mounting the rear sight. I've discovered that many bolt action receivers are very similar in their diameters which means their contours are similar. This greatly simplifies the task of finding a sight that will fit this rifle. The sight I ultimately used was a very common Lyman 57SME. This sight was originally designed for the (S)pringfield, (M)auser, and (E)nfield. It is also designed to be mounted on the right side of the receiver, but needs to be mounted on the left side of the Mosin receiver. Mounting it on the left side of the receiver however, would mean the aperture would be backwards. To alleviate this problem, I simply disassembled the aperture from the windage screw, turned it around and re-installed it on the screw.
I wanted to position the sight so I would still have the option of using the stripper guide. This made mounting the sight a little tricky as the rear of the Mosin receiver tapers which means there's not much metal for the rear of the sight base to rest on. But I was able to find a happy medium. The front of the sight base, where the front screw is installed, is fully supported making near 100% contact with the receiver. The rear is not nearly as supported, but with two mounting screws I was able to mount the sight plenty sturdily.
So here's the outcome:
My next step is to order a Scout type scope mount and make a Scout rifle out of it. Until then, I'm going to bed it, shoot it, and look into options for a ball type bolt handle with a flat base portion for mounting to the Mosin bolt body.
35W