Mosin Nagant Russian surplus cracked case

[easyliven88]

I took my MN out for a day at the range and everything went quite well, nice groupings and my trigger pull shortning/polishing has really made a difference. But, once I started picking up the casings I had a few with some deep gouges and one with a complete split.

The rifle fired beautifly and I didn't notice anything weird during the session. Is this just really old surplus ammo, anyone else ever see or experience this. Here is some pics.

[steinauge]

Looks like old ammo to me.I have a batch of 8X57 that is dated 1939 and will do that about 2 out of 10.

[Stukaman]

Almost all the polish 7.62x25 I've ever shot did that.

[easyliven88]

So my question is will this hurt the MN? I mean the ammo looks in great shape before being fired, I just don't my breach to shrapnel-ize my face

[Punisher_1]

Could that be a headspace issue? Maybe the rounds aren't fully seated?

[tobnpr]

Could definitely be a headspace issue.
Those case splits aren't at the case necks- they're at the shoulder, and extending down towards the case head.

Is this something "new", just now- with a different batch of ammo?

If so, probably bad ammo. You need to try some other ammo. If it happens with other ammunition, you might have a chamber problem...

Split cases mean the case isn't sealing against the chamber wall- and you're losing combustion gases. Could be the ammo- could be a potentially dangerous rifle. You need to find out which.

[easyliven88]

I've shot about 40 rds of PPU all brass and didn't see anything like this...I took it to local smith when I got it for a safety check, he told me that since its all matching numbers, the Russians gauged them before cosmo coating and storing them. I guess I need to spend a few more dollars on some better ammo. Thanks for the info/replies my fellow shooters....

[ToddG]

I had the same concern when I got mine. Don't worry, shoot happy.

If the split starts getting down to the base you might change ammo, but this old steel case stuff just does that. Search other thread for similar--and even scarier--pics.

[amx4080]

I've had splits like that with 3 surplu cartridges out of thousands in different Mosin Nagant rifles. The surplus steel does it occasionally. You most likely didn't see it happen with the new PPU ammo because it's brass, and it's new.

If you're concerned, get the rifle checked.

[tobnpr]

If it's not doing it with brass cases, I suspect it's OK.
Brass cases expand better than steel.
But, I'm very surprised, that you took the weapon to a "gunsmith" for a safety check, and he certified it as "safe" based on his assumption that because it has matching numbers and supposedly was checked by some armorer 75 years ago makes it so...

I'd find another gunsmith. That's ridiculous.

[easyliven88]

Checking for headspace there are Go...No Go...Field...Do I really need all 3 or can I just purchase 1?

[tobnpr]

You def don't need a go gauge...they're used for installing new barrels/re-chambering.

A field gauge will determine whether the rifle is safe to shoot. If it fails a field gauge, it's a wall hanger.

A no-go gauge will tell you if the rifle meets what many (including CMP) meets minimum standards. If it fails the no-go, it means that it has excessive headspace- and is on it's way out- but it might still be "safe" to shoot (if it were to pass the field gauge).

I use a no-go. If you're just interested in determining whether the rifle is safe, get the field gauge.

[HankC1]

Mosin Nagant is rimmed ammo, headspace gauge may not detect a neck space issue when headspace is set on rim. Seems like split case is quite common for Mosin Nagant, I saw many spent casings with split necks at shooting range. I don't personally own a Mosin Nagant.

Edit to attached picture of split casings I found at a shooting range. Many of them in trash can!

[easyliven88]

HankC1, I guess its just old steel casing doing all the splitting, since I shot over 40 PPU rounds with nothing like what I saw on the Russian surp stuff.

Field gauge it is then, just to be sure, wish they were rentable lol. Thanks again for all the help. Btw tobnpr, I checked out that link at the bottom of your posts, you have some beautiful stocks there. If I get a hair up my butt to sporterize another MN I'll be using one of them with the adjustable cheek rest...

[tobnpr]

Thanks, appreciate it. I couldn't find a quality stock design for my modded long-range Mosin, so I made one. After some requests, went commercial with them.

One other idea- not very scientific, but done all the time...if you get a no-go gauge, you can place a single layer of cellophane packaging tape over the back of the gauge. The added thickness approximates a field gauge (about .003 added); if it closes on the no-go, add the tape, and check again. If it doesn't close, safe to fire. If it closes, wall hanger.