Case head separation mosin nagant

[repawn]

Actually not sure where to put this - was shooting some reloads this weekend - had my 1st and 2nd case head separation (partially) I didn't notice anything while shooting - probably a testament to the strength of the MN.
The brass was something I bought as 1-fired - but it may have been used a bit more. http://img.tapatalk.com/d/13/05/14/a8age2ys.jpg
http://img.tapatalk.com/d/13/05/14/4e2utu4y.jpg

Anyway - going to check my brass a bit more closely. These were loaded with 44gr h4895 under a 174gr bthp. I need to find a good cast boolit for my mosin :)

[Larry Gibson]

What you need to do is NS the cases instead of FL sizing them. I haven't lost a case to incipient head seperation since I started NSing my 7.62x54R cases for my MNs. There is a very wide variation of chamber sizes in MNs so FL sizing or even partial sizing with a FL die sizes the cases too much, especially in the web area. I have some Norma cases I've loaded a lot with jacketed and cast bullets since the '70s.

Larry Gibson

[wallenba]

S&B is usually very good brass, I think it is what Winchester puts their headstamp on. The shiny area below the separation, if it was there before firing, might have been a clue something was amiss. Like as said, neck sizing could benefit. Try and locate some headspace gages. Okie http://www.okiegauges.com/ makes ones that don't require the removal of the extractor. I don't know how long you have owned the rifle, or wether or not this is a new problem, but new and used bolt heads are available at Numrich, should you have a headspace problem. It's a 'pig in a poke' fix though, as you never know what your gonna get.

The case heads themselves look almost new, as though they have not passed through many guns. That worries me a bit. Use a dental pick with a small hook on the end to reach in and feel for a 'dip' in height of the inside wall in that area of any unfired cases from that batch.

On an additional note: I have seven MN's, and I've swapped the bolts in and out of them, checking for headspace issues. In my experience, they have all passed in every one I tried this in. The only real issue was, how the bolt heads had worn into their respective correct rifle locking lug recesses.

[repawn]

No problems with the rifle. The brass was bought off a different forum - I needed to fl resize it as it wouldn't chamber with just a ns. Also, I had to fl size twice as the 1st time I used the .308 expander but I am running .312 bullets through it. So after getting the larger expander I ran them again. So the brass was worked quite a bit more than usual. I don't have a collet sizer for 7.62x54r but I'd do use the lee loader once they have been fired in my rifle.

Going to check the s&b brass with a paper clip.

[tomme boy]

S&B and Win 54R brass is ****. It is too hard and the primer pockets are not the right size. Too shallow. Other than that, neck size the brass and it will last wayyyyyyyyy longer.

[leadman]

I treat all of my rimmed bottlenecked cases as if they were rimless, headspacing off the shoulder. If I get range brass or used I size it just enough to fit my gun. Sometimes this is bottoming out the die against the shell holder but most of the time it is not. Fireforming full length sized brass with fast powder and Cream of Wheat cereal also helps the longevity of the brass.

[repawn]

Thanks all for the advice - what do you all do with new brass? Do you fireform it then load - or just load it and go? I have a bunch of new lapua that I haven't touched yet.
I started with a bunch of PPU ammo - and have had great luck reloading it - nice brass and the only issue I have had with that is one piece with a loose primer pocket after the 5th reloading.

The S&B stuff was previously fired - this was the first time I fired it- I still have 10 rounds loaded up - but I am checking my empty brass for signs of separation. I should mention that I did shoot about 10 other rounds of S&B with no problems - I will most likely just fire off the 10 rounds if they pass a visual inspection.

last comment - I didn't even notice the cracks int he brass until after I pulled them out of the tumbler - they ejected just fine and I just tossed them in the bag - I usually will check a few pieces for signs of pressure - then do a thorough check after cleaning.

[texassako]

S&B and Win 54R brass is ****. It is too hard and the primer pockets are not the right size. Too shallow. Other than that, neck size the brass and it will last wayyyyyyyyy longer.

+1 to that. PPU cases lasted a lot longer than the S&B I had. I would toss the rest of those cases, or at the least carry a broken shell extractor in my range bag.