Reddit reviews Mosin Nagant Headspace Gauges - 7.62x54R 3 Pc Set - Go, No-go, Field by Firewerks

If you're worried about the bolt, and want to make extra sure it's within tolerances, you could always get one of these. The explanation on how to use the gauges is found here - please go through the tread before forking your $$$. As the users on gunboards mentioned, most of the times the field gauge is just enough (can be purchased separately).

Here's some info from a guide i've been working on. Runnybear's guide over on the /r/guns FAQ is a great place to start but I tried to pick up on some of the stuff he left out. Also I held out on including a hidden goatse, for better or worse.


BUYING:

FACTORIES: Russian Mosins come from two main factories: Izhmash and Tula. 91/30’s (Made after 1930) Izhmash is depicted by a triangle with an arrow in it. Izhmash before that is depicted by a small bow and arrow. Tula is depicted as a star with an arrow in it. Some people swear by Tula, something to do with less being made by them and they got the instructions before the Izhmash plant did and could start producing them earlier, but I have yet to find any solid evidence that would indicate one being better than the other. Regardless of whether or not any difference is present, online gun retailers have capitalized on such views and will charge you extra (10-20 bucks from what I’ve seen) for a Tula. Again, that does not indicate that they are better, they’ve capitalized on people thinking (which may or may not be true) that Tula’s are better. For reference both of my Mosins are Izhmash (’42 refurb and a ’44 Ex-PU Sniper) and work just fine. If there’s a spotless, sparkling Izhmash and a rusted or beat up Tula, I’d go with the Izhmash. Don’t think of Tula as some holy grail with steel forged by Stalin himself in Lenin's tomb.


REFURBS: Check the stock and receiver for a small symbol that looks like a square with a line either going diagonally through it or vertically through the center. This would mean that your gun was taken and re-finished and touched up at a Ukranian Arsenal in the 1970's. Up to you on whether or not you want a refurb. The refurb process basically touched up the rifle and may have swapped out or replacement parts. Your call if you want to go with a refurb, some people say it “takes away from the collectible value” or whatever but when it comes down to it we’re talking about a 150 dollar rifle so the “collectible value” might be an extra 20 bucks. If you’re looking for a good shooter, I wouldn’t scoff at refurbs. Parts were replaced due to being worn out or beat up. When looking at a refurb definitely check for a COUNTERBORE (described below).

EX-SNIPERS: In your journeys you may find a 91/30 that was a sniper-model originally. 91/30's that had exceeded accuracy standards were given a scope, bent bolt, and a better trigger system and issued to snipers. As the war dragged on, the need for infantry rifles outweighed the need for sniper rifles, so they started stripping them of their scopes and re-issuing them as infantry rifles. To see if said rifle is an ex-sniper, look for a few signs. For starters, check the receiver to the left of the factory stamp and date (on the side of the rifle, just above the stock). Do you see a separate serial number with a line stamped through it? This would be the serial # of the scope on your rifle that was removed. To check further, open your bolt and inspect the inner receiver wall. Do you see 4 holes about the size of a pencil eraser in the wall of the receiver? These are spots at which one point the receiver was drilled and the scope fastened in these holes with screws. Also look for wartime productions with very smooth receivers. This is not always indicative of an ex-sniper, but sniper models were given nicer finishes at the factories than their infantry brethren. While a standard wartime 91/30 would probably have grooves or a rough surface, ex-snipers have smooth, finished barrel shanks. Also look for a "C" stamp, this is indicative of a sniper mosin. Ex-snipers are generally worth a bit more than a regular Mosin, and the trigger is much nicer. Also they were originally more accurate than their infantry brethren, but that may or may not be true today. It does make the rifle unique though! Also, on my '44 Izhmash Ex-Sniper the bolt seems to move smoother and more quietly when working the action, and i've noticed at the back of the receiver on mine the path that the bolt travels has some angled grooves, almost like rifling. Not sure if that has anything to do with the bolt being quieter/smoother but it's there.

COUNTERBORE: Also check the muzzle to see if it has been counterbored. What this means is that for whatever reason (dinged up by cleaning rods, rust, Ivan tried to fight a rock with it) the muzzle crown was messed up, and the Soviets re-drilled it to “improve” accuracy. A simple way to check this is to take your average 7.62x54R round and insert it into the MUZZLE, bullet first (pointy goes in). If you can press the bullet itself in up to the casing around it, it was a counterbore. If you find resistance and can’t push all the way to the casing neck, it was not counterbored. Counterboring affects the accuracy and is generally not desired.

FIELD STRIP IT: Look all over for rust and pitting. Even though these things were seemingly tossed in a cosmoline vat, rust can still be present on these rifles. Taking the rifle apart is super easy. Start by making sure the firearm is unloaded. Then, pull the bolt back all the way. While pulling the trigger, pull the bolt back further to free it from the receiver. Then, slide the two metal bands on the stock (holding the wood on the barrel) to the front of the rifle. This should allow the top wooden cover of the barrel to free and come off. Then take a Mosin tool (or flat-head screwdriver) and you’re going to remove 2 screws. One is on top-back of the receiver, just beneath where the cocking knob sits when the bolt is closed. The second screw is underneath the rifle, at the front of the magazine. Take these two off, and you can pop it right out of the stock. Look underneath the rifle and all over it for signs of rust or pitting (little pocks and divots caused by rust eating into the metal). Avoid rust like the plague, it’s not your friend and it could cause a serious problem when firing. Once you have field stripped it, you could probably do it again blindfolded. It’s like the world’s easiest puzzle, with two screws and 2 metal bands (not like Slayer or Megadeth, but circular loops of metal to hold the stock (you came for the guide, but stay for my piss-poor attempts at humor!)).

ELECTRO-PENCIL: Check the bolt, magazine, and floorplate to see if they have matching serials stamped into them. They may have the original stamped numbers lined out (or not visible) and the presence of Electro-Penciled numbers (bottom picture here ). What this means is that these parts are not original to the rifle, but were "force-matched" from other rifles to fit it for any number of reasons (the original bolt on your rifle may have been ruined, or magazine broken, etc etc). Think of it as a "Frankenstein" gun, with parts from other Mosins being part of it. This is an indicator of a ARSENAL REFURB, described above, and you may want to take that into consideration depending on what you are looking for.

HEADSPACE: I would either headspace it yourself or have it headspaced by a gunsmith before firing, you can buy gauges from Amazon for around 20 bucks IIRC. I use the No-Go and Go gauges from Firewerks. You will need BOTH a Go and No-Go gauge to measure the headspace, the rifle must pass both checks for it to be considered properly headspaced and safe to fire. They involve a simple test using a little gauge that you place on the front of the bolt and then cycle the action. I wouldn’t imagine any gun store to have a problem with you checking headspace. There is also a “Field” gauge that can be used should the Go and No-Go gauges failed, but this kind of indicates that your gun is in a grey area of safety and should probably only be shot using modern commercial ammunition (I wouldn’t buy anything that didn’t pass both the No-Go and Go test).

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I have the field gauge from this set. It's pretty easy to use since you don't need to take out the extractor.

Liberytreecollectors.com has some M91 bayonets in stock. I'm going to try to get one later once I start getting paid. They're not cheap though. You can also get an M91 cleaning rod from them. I'm guessing you already know all of this though. Good luck with the sling, that might be hard to find.