These are answers I've given to questions asked about the Mosin-Nagant around the web. Feel free to use them if you think they're accurate!
What is rimlock?
The Mosin-Nagant has a feeding system which employs an interrupter. In
theory, this should keep the top round separated enough from the bottom
rounds to avoid rimlock.
In practice, wood is compressed and rifles are improperly inletted, especially when manufactured hastily in wartime. Wood can also shrink with moisture loss, and this will allow rimlock to occur.
Shimming or bedding will solve the problem of rimlock in the Mosin-Nagant. You simply want to elevate the receiver a bit. Properly done, this has the added benefit of adding known pressure points to the receiver and barrel, and will shrink groups. The Finnish HV (jam-free) mag is modified to give extra protection against rimlock and was used on all M39 rifles and most M27 and M28 versions, as well.
$ 60 USD
For specially troubled Mosins. Cures rimlock where other methods have failed.
• Tweaked interrupter
• Full accurizing shim kit
• Added magazine toe shim
• Finnish HV (no-jam) magazine
Please make sure you're using the two-piece ejector/interrupter assembly. The one-piece interrupter/ejector assembly will still work with the shims and the HV magazine, but you'll not be able to use the tweaked interrupter unless you have the two-piece assembly.
Free shipping within the United States by Priority Mail. Ships in 7 to 10 days. I cannot ship these internationally.
What ammunition may be used in the Mosin-Nagant?
You cannot use anything but ammo marked 7.62x54R or 7.62x53R (same thing; the latter is the Finnish designation).
Some early Mosin-Nagants that found their way to America (or stayed here after Russia defaulted) were rechambered in .30-06, but they are rare AND ARE NOT SAFE TO FIRE.
Someone (I forget who) does manufacture a chamber insert that allows .32 handgun ammo to be fired from the rifle for low-noise practice, but I've never seen the need when one can just load a few rounds with Trail Boss.
Please, do not blow yourself up.
I am getting corrosion on the bolt face and don't know what it's from.
Your bolt face should not be affected much, if at all -- are you piercing primers?
So-called "corrosive" ammo has potassium chlorate in the primer. Upon firing, the potassium chlorate deflagrates into potassium chloride, which is very similar to table salt.
The salt in and of itself is not corrosive. It is extremely hygroscopic, though, and attracts moisture. The higher the humidity, the more and faster the rust will form.
If I fire surplus through my firearms, I run a slightly soapy patch through the bore, then follow it with two wet patches, two dry patches, then clean as normal. The soap must be completely removed as it will attract moisture, too!
In a perfect world, the cartridge case would expand and prevent gases from coming back against the bolt face. However, this is not a perfect world. Check for firing pin protrusion using the gauge/screwdriver that came with your rifle, and look to see if you pierced any primers. When cleaning, wipe down the bolt face with oil, or take the bolt head off and clean it as you do not want to get water or soap (hygroscopic itself, remember!) into the firing pin channel.
Cheap centerfire rifle? Are Mosins junk?
I would recommend the Mosin-Nagant.
People are right in that they're cheap. What they get wrong was the reason why. Importers are buying the rifles at what are essentially scrap prices. The Russians are looking to unload them any which way, and they prefer to sell them. However, if they didn't have buyers, they'd just toss them into some body of water or another.
The Mosin-Nagant is inexpensive, but not "cheap". If produced today, a Mosin the quality of a pre-war example would cost $600 to $800 to PRODUCE. I do not know what the retail markup would be, but I would suspect it would be at least a couple hundred dollars.
Properly made, they are capable of 2.5" at 100 yards. My personal 91/30 will do under an inch with handloaded ammo, though I have done a bit of accurizing to it (adjustable front sight, shimming, pressure pad, trigger work).
The WWII snipers found that wrapping the barrel in oiled felt would improve the precision as well.
You will have many people telling you that the Mosin-Nagant is not an accurate rifle. These are the same types of people I love to prove wrong. I have outshot many modern rifles.
To be fair, however, you cannot compare the Mosin-Nagant to a modern, precision built bolt-action rifle. Neither can you compare the prices -- a good, modern bolt-action rifle will cost at least thee times what a good Mosin-Nagant will run you, and likely much more.
When I want precision, I grab my set-trigger target precision rifle that will knock around a ping-pong ball with ease at 100 yards.
If I want to have fun, plink, or need a serious, non-complicated rifle, I grab the Mosin.
The Mosin-Nagant will shoot better than most shooters are capable.
I have trouble affixing (or removing) my bayonet. Why?
The Mosin-Nagant was made to have the bayonet affixed in battle. In other words, the Russian philosophy has been that the rifle is a carry vehicle to use to get to within bayonet range.
The rifles were even sighted in with the bayonet affixed -- something that is important to know as the point of impact will change with the bayonet on or off.
Due to this reason, the bayonet is very difficult to put on or remove, many times requiring that one use the takedown tool supplied for leverage.
Many outside the former USSR find this distasteful. The fix is to use a bit of coarse-grit sandpaper on the inside of the bayonet socket.
You can use your finger to go the circumference, or split a 6" dowel rod to about 1" from the top, wrap a piece of tape around the base of the cut, fold a piece of appropriately sized sandpaper in half, insert into the split in the dowel rod, chuck the dowel rod into a drill, and polish the inside of the socket until the bayonet is relatively easy to put on and take off.
My Mosin-Nagant gets very hot and sweats cosmoline while shooting. Is this normal?
You have cosmoline in the wood.
Take the stock only and wrap it in newspaper. Set it outside or in a car trunk on a hot day. This will get rid of the majority of cosmoline.
The rest, just wipe off when it gets hot. It will eventually stop sweating the stuff.
As for getting hot when you shoot, the answer is that yes, it will. You have what is essentially a controlled explosion happening in your barrel, and you have metal-to-metal contact at 3000fps. You know how disk brakes get hot? Same idea.
It's not unusual for AK variants to start smoking and sometimes catch fire if fired rapidly, and the bullet is going about 500fps slower than from the Mosin-Nagant!
You have a powerful tool there, and you're seeing the byproducts of that power.