7.62x54R Overpressure?

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Joshua M. Smith

Joshua M. Smith

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Hi All,

I sure could use some help here.

I don't know much about overpressure situations. My new-to-me M44 Mosin-Nagant was exhibiting a "sticky bolt" while shooting some Russian surplus ammunition from 1986.

It has no problem shooting heavy ball from Hungary made in 1951. The action is very slick using that stuff and I can reach over and operate the bolt handle with no problem (I'm a lefty). The ammunition is copper washed steel.

The Russian stuff is light ball. It has a laquered case mouth and primer, and the case is not laquered. It is copper washed steel as well.

When I first fired it I could hardly get the bolt open. I then came to the internet forums and found that the Mosin-Nagants have "sticky bolt syndrome." I followed the steps to correct this.

While it helped somewhat, the problem still existed.

I took a closer look at my spent cases. This is typical of what I found on the Russian stuff.

Overpressure2.gif
At first I thought these were a couple scratches, perhaps manufacturing defects.

Overpressure1.gif
I then noticed that the case is cracked, with light visible through the crack.

The rifle is OK. It's sturdy, if not purdy :)

Can someone tell me if this is a sure sign of overpressure? I don't know what else to look for; I've never seen an example of a flattened primer.

The bands which go around the cases look to be from some sort of annealing process. Looks like other heat treated metal I've seen.

Also, this ammo blows moisture of some sort back. Is this indicative of anything?

Overall, what exactly am I looking at gents? Over pressure, or is this typical of Russian stuff?

Personally, I think hard extraction + random case ruptures = overpressure.

The case code is "60" at 12:00 and "86" at 6:00 for those who may be wondering. I do not have a lot number.

Any help is appreciated.

Thanks,

Josh <><
 
Well I honestly can't say exactly what that means, but I've never had it happen. Only shot about 150 rounds of 54r though. Glad nobody was hurt, these guns really are built like tanks.

The sticky bolt situation is very common though and doesn't mean a whole lot. If anything just clean out the chamber... I believe people use a 20gauge shotgun bore brush attached to a drill to clean the chambers usually.
 
I've fired about 700 rounds of Russian surplus from the same factory ("60") but production from two years earlier ("84"). Mine exhibits the same color banding that yours does, but I haven't had any problems with ruptured cases. I've fired it from a variety of rifles, too.

I don't have the technical knowledge to answer your question about overpressure, though. :(

Russian surplus on the right in both photos.

jm

russian_albanianx54r-1.jpg

russian_albanianx54r-2.jpg
 
What does it mean when a shoulder is blown out? The chamber specs out good btw.

I just compared the primer to a new round. The new round looks as if the primer is sitting in there too deeply while the fired primer looks like it backed out some and mashed up against the bolt face.

Josh <><
 
The Polish light ball seemed to do this with all my Mosins. I have had some split halfway down the length of the case. Most just do what you show in the pics. It seems like a lot of people have this happen. Maybe I should, but I don't worry about it too much anymore. Ive always thought its caused by the case neck not expanding well enough and it tears/cracks in addition to being loaded a little too hot. It seems to mostly happen with steel case ammo with the occasional brass case. Hmm, maybe I should worry about it.
 
I have had case splits with Polish (steel case) and Bulgarian (brass case) in multiple Mosins (91/30, M44, M39). It seems to be a pretty random event, at least in my experience. I just make sure that I wear shooting glasses at all times.

If every case is rupturing, you could try indexing the cartrdidges. Mark a potion of the case head and individually load each round with that mark in the same relative position. After shooting, check for case ruptures.

If the cases always split in the same position, you may have a chamber issue. If they occur at random positions, the ammo may be the issue.

I would also check the chamber for burrs, if I were you. My friend had an M44 that had a sticky bolt due to a sliver of metal gumming up the works.

Good luck.
 
I'm going to go out on a limb here. After seeing the two unfired rounds next to each other it appears as though the Russki ammo's shoulder begins a tad earlier. So perhaps with an inspec chamber you're pretty much fireforming steel cases beyond their limit every time you pull the trigger. That would be consistant with the blown out shoulder and rupture.
 
The ammo is fine...

most problems come from improper bolt manipulation. I've shot thousands of every type of x54 ammo out there and this happens with different kinds. Most of the time the MN likes a good slap "up" then straight to the rear. I've never had to use a Mallet or 2x4 to open the bolt on a properly cleaned chamber/bolt. Ensure the chamber/bolt (stripped) are properly degreased and clean. This means scrubbing the chamber with a 12 gage brush (on a cordless drill)and some WD40, disassembling the bolt all the way down and cleaning all the old gunk out of it. Reassembling the bolt and apply small dabs of grease to the moving parts. Finally ensuring the locking lug recesses are from from grease as well. This will usually cure all of the symptoms.

You may be handicapped a bit because you are a "lefty" but a practiced bolt manipulation will often work wonders......
 
Jeremy,

It's just an initial "stick" as the bolt comes up and begins extraction around the same time it cocks. After that I can pull the bolt back just fine. It's just that initial "break" where whatever sticks breaks loose. I don't have this problem with the yellow tip stuff I have, so it's not a spring issue.

I did do the chamber cleaning thing, though I used a 20 gauge brush.

Josh <><
 
I don't know what this means, if anything, but I just tried to chamber a spent Russkie shell and the thing won't go in. It looks like it has a slight bulge about 1/8" up from the rim. This is what is sticking.

The surplus yellow tip empties chamber just fine.

Does this mean anything?

Thanks,

Josh <><
 
Never, never use surplus ****!! Kauko
Click to expand...

Considering that millions of rounds of Milsurp have done fine in these rifles over the years, I don't consider that very sound advice.
 
Can someone tell me if this is a sure sign of overpressure? I don't know what else to look for; I've never seen an example of a flattened primer.

--Not overpressured, just old brass. case seperation at the neck isnt anything to worry about, worry about it once you start seeing seperation around the head.

Also, this ammo blows moisture of some sort back. Is this indicative of anything?

--Thats probably melted cosmoline, lol, best wear your safety glasses.

Overall, what exactly am I looking at gents? Over pressure, or is this typical of Russian stuff?

--Typical for all milsurp, keep on shooting it, hasnt blown me up yet.

I'll state the obvious, inspect the round before loading it up and firing it, if it shows signs of corrosion or case failure before firing, then dont use it.
 
That pic posted by grimjaw shows exactly what I found with a bunch of Albanian ammo (aresenal code 3, date code 88)

BIG dings in the case necks and case body & damaged "crimp" areas. Some of those rounds were so loose I could pull the bullet with 2 fingers.

Those got the bullets pulled, powder dumped and primed brass soked in water for 3 days.

I have also run into a few rounds from the '88 Albanian stuff I bought that refused to let the bolt close. "...Upon further review...", I found that the rim was flat, like a .30-30 round, rather than beveled.
 
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Sticky bolt is caused by two main ingrediants. Cosmoline and steel case ammo. The last little bit of cosmoline that you can hardly ever get out will warm up and ooze out onto a steel case and basically act like glue!

I used break fluid and a 45cal brass brush on the end of a cordless drill as well as any other solvents I had lying around. It helped but too many surplus steel cased ammo shots in a row will start sticking again no matter what! I've had a rubber mallet in my range bag for a while now!

Brass cased ammo works like butter!
 
Stop worrying about it and just shoot the darn thing!:rolleyes:

If this was back in 1943 and you were a Russian soldier, I suspect the sargent would have told you the same thing, only in a more direct way.
 
Thanks All,

So far as I know zinc is not involved. The cases are advertised as copper washed steel with red laquer sealant.

I do not have the pic of the SPAM can it came out of... but I do have some other pics for ya'll:

flat1.gif
Head-on primer view, comparison fired and unfired.

flat2.gif
I'm attempting to show the primer depth here. I don't know if this is normal.

Dsc00026.gif
Case length comparisons.

Is it just me or does the OAL of the Russian stuff look to be shorter than the Hungarian heavy ball? Photos don't do it justice; the unfired Russian case is definitely shorter in length to the shoulder and to the mouth.

bulge.gif
Circled is the bulge which will not let me chamber one of these spent shells.

The bulge is present on every fired case I've examined, and is the reason it's not extracting properly. The laquer has very little to do with it and there can't be any cosmoline left in the chamber anyway, after the cleaning I gave it over the course of two days. Remember, this involved a 20 gauge brush and drill as was recommended.

I was told that the burn rate can change over the years. The ammo is moved around and while it may start out as granules or flakes, the continuous movement gradually makes it finer. Does this make sense?

Any more comments? It's only doing this with the Russian light ball.

Thanks,

Josh <><
 
I was told that the burn rate can change over the years. The ammo is moved around and while it may start out as granules or flakes, the continuous movement gradually makes it finer. Does this make sense?
Click to expand...

False......


I'd say for now just stop using the Russian Factory "60" ammo. For whatever reason "your" rifle doesn't like it. I have several MNs and they all ate it up...matter of fact it was really good ammo. Some rifles can be "finicky" when it comes to ammo. Lots of MN shooters had a horrible time with the Czeck laquered cased ammo....I however didn't have any issues and my rifles shot it with no issues.

No worries on your rifle just shoot some other ammo in it!
 
And it could be you got a bad can of it. I don't think those primers are normal, nor the variance in case length. Looks like a lemon of a can. Other cans of same date/arsenal are probably fine.
 
Thanks guys.

I think I'm going to go with my gut and not fire this stuff after firing my Hungarian heavy ball.

That stuff works very well - it lets the action work almost like there's not a round to be extracted.

Since I polished things up the bolt feels almost like a stock Rem 700 (I know... blasphemy). The Russian stuff I bought may or may not be safe, but it doesn't feel safe and it's really not fun to shoot when I'm dreading working the bolt.

Thanks all... you've been a great help.

Josh <><
 
--The 54R headspaces on the rim, not the shoulder. A blown shoulder may be evidence of a poorly crimped round with a fold in it. Albanians are notorious for wrinkled crimps. If the steel case has gotten stiff and old it may simply crack instead of reforming to fit the neck. I toss the rounds with folds in the neck.

--Case length varies considerably in 54R/53R. Within a mm or two it's of limited importance as long as you can chamber the round.

--Primers in 54R are generally quite deep, and they're supposed to be. It's not unusual to see them backing up to flush. It's also not unusual to see what looks like too much flow. This is often not because of overpresure but because the pin hole is too wide and there's a gap the primer can flow through. I only get worried if I'm actually punching primers all the way through, at least if it's not a pin protrustion issue.

--There is enormous variability in chamber dimensions and specs between various Mosins, even those made by the same nation. If your Mosin chokes on a particular type of ammo this is not all that unusual. Just stop using that type.

--All fired 54R I've seen has some stretching near the rim. What you need to look for is an incipient separation ring, not merely a stretch mark. This is usually a clear ring that can be seen above the stretched area, possibly with some space already peeking through. Do not confuse this with the change of metal color found on bimetal cases.

--The Mosin and 54R combination is very tolerant of poor headspacing and 90% of the time stuck bolts are due to chamber oddities (your bulging perhaps) or a poor chamber/cartridge combination. A Mosin with bad headspace will usually pierce a lot of primer pockets and you'll see the separation line in the fired brass. I've only ever shot one, a very badly worn out M-28.

--It's highly unlikely that older 54R would be really overpressure. Usually this is not what causes sticky bolts, anyway.
 
Is that picture with the red line around the neck and the wrinkle Albanian? Ive got a few packs of that crap and never could figure out what it was, but man whover made it sure sucks, the rim is like a 30-30 rim
 
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