Love my new Sweede, but...

[aagiv]

This week I purchased a beautiful M96/38 Carbine, my first Mauser. It is a Gustaf gun manufactured in 1900. All the numbers match except for the front swivel sling/barrel band, and the stock is dark with a good grain. It does have a number 3 barrel, but I didn't worry about it because the rifling looked good and I have read that a #3 Sweedish barrel can be as good as any other Mauser barrel. I took the rifle out shooting, and inspected the first couple of cases after firing. They seemed to have stretched a little compared to the unfired cases, but not enough to worry so I went ahead and finished off the box of ammo. As I was collecting my brass, I noticed that one of the case necks had split. It was a small split, about a 1/4 inch long originating at the case mouth. I was somewhat concerned by this, so I loaded up the rifle and took it to a local gunsmith. His verdict was that the split was due to throat erosion, and that the gun was safe to shoot, though the accuracy might leave a little to be desired. I haven't fired the rifle since then, because I have a little doubt about his "safe to shoot" prognosis.

Is this guy correct, or do I need have something done to the rifle? I know some of the importers have unused barrels to fit, and the rifle is worthless to me if it isn't a shooter, so I could sacrifice the matching numbers for a new barrel. Inicidently, I didn't do any real accuracy testing with it, but firing offhand, it seemed to shoot where I aimed, and the bore is excellent.

 

[bullfrog99]

if you are a re-loader you can fire form your cases with a 70% charge an only neck size, then set the bullet long(hopefully it will still fit in the magazine) to the rifling. that should work. another option is to have someone take your barrel out, set it back a thread or two and re-chamber it. shouldn't cost too much. maybe 150 bucks? not sure. i know it will work just never done it. re-barreling is another option but that costs more, and you loose the sights(unless you find another mauser barrel)

 

[James K]

I have to question the gunsmith's statement about throat erosion.

You can usually tell that bad throat erosion simply by looking in the barrel. Use a good light from the muzzle and look carefully at the rifling just ahead of the chamber. TE will show up as washed out rifling. TE is flame cutting, and by definition washes out the rifling in the throat, which is ahead of the case neck. It does not affect the case neck area.

In other words, TE should not cause split necks.

You don't say what kind of ammo you were shooting or how old it is. Case neck splits are usually the result of seasoning cracks on old ammo or repeated working of the brass in reloading. Case stretching can be due to excess headspace or again to reloading.

Hold off doing anything to the rifle until you check out other facets of the problem.

Jim

 

[aagiv]

The ammo was Winchester factory loads, so I have to assume the brass was new, never fired. When the cases stretched, the base of the shoulder didn't move. The amount that the front of the shoulder moved was about equal to the amount that the OAL of the whole case grew, about 1/16 to 3/32 of an inch--just enough that I could tell when compared to an unfired case. The case mouths stretched to the point where they would just slip down over an unfired bullet.

 

[Gewehr98]

I've seen PMC 6.5x55 ammo do that, but...

That PMC fodder was very much overpressure, with flattened primers, visible stretch rings, and split necks. As for Winchester ammo, it's the first I've heard of that happening in the venerable Swede. Maybe we could get some more info out of your experience? How did the gun feel during firing, what did the primers look like, what grain bullets were they, what accuracy was achieved, and did the aforementioned gunsmith mention anything about checking out the headspace? (As a gunsmith, I would worry more about that than I would the throat, as the throat really isn't considered part of the chamber proper, as mentioned by Sir Jim above.)

As for the fired case mouths being able to slip over a bullet, that's quite common, especially in military rifles, they have larger chamber tolerances than your typical benchrest/varmint rifle to withstand the grunge and ammo of wartime.

If it is throat erosion, remember that the earlier M-96 Swedish Mausers were designed for the longer 157-160gr bullets, so if you reload, you can seat those flying telephone pole bullets out further to offset some of that erosion if need be.

 

[aagiv]

The brass showed no extreme signs of stress such as flattened primers. Like I said, I didn't do any real accuracy shooting--just a few quick shots offhand. I had planned to use the next box of ammo for accuracy testing, but I quit shooting after finding the split neck. Bullets were 140 grain soft points.

Perhaps you can help me with the exact definition of headspace. I know it has to do with the distance from the shoulder to the bolt face, but what part of the shoulder? The base of the shoulder did not move at all, just the front edge of the shoulder. I really don't see how the throat could cause the neck to split; that's why I was leery of the smith's diagnosis.

It was a small split on one case out of twenty. I suppose it is entirely possible that the case just had a weak spot.

 

[Gewehr98]

Then it's entirely possible...

If it was just one piece of brass out of the batch, I've seen that happen several times, once with a batch of Federal Match .308 in a 700PSS, and once with a batch of brand new Bell .45-120 in a new $3K Shiloh-Sharps, at a cost of $2.00 a piece!

Since your shoulder at the case didn't move much, but the shoulder at the neck moved more, I'd think your headspace really isn't that far off. Take the rest of the fired brass, and measure the case length and case diameter near the head, comparing it to some unfired ammo from the same batch and lot, if you can.

As you said, it might just be some weak brass. That would be an easy fix.

 

[Cain R]

I have the exact same problem with my 6.5x55, mine was made in 1900 by Waffenbrik. When I got it the stock was butchered and the bolt crudely bent. But my that rifle shoots! Except I only get about three loads from the brass. Federal, PMC, Winchester etc. I have the identical problem with my Enfield .303's the case necks split after three reloads. I've been told by several 'smiths that the problem lays in the rifles military past. Often chambers are cut slightly over size to feed dirty, muddy battlefied ammo with no problem. This usually crops up after more than one reload though, but I had a batch of PMC and Federal that burned through on initial firing and now have Winchester and Remington brass that have had three reloads each. Your rifle may be just that much over sized. For plinking try finding some Swedish mil-spec surplus, we get then for about $25.00/100 they are steel cases and non-reloadable cases. I put about 100 rounds per year through my old girl and have had zero reprocussions with the neck splitting.

 

[aagiv]

Cain,

Where do you get your surplus Swedish ammo?

 

[Cain R]

The last batch was from "The Soldier Shop" in Calgary Alberta. This was two years ago, and I've bought some since at "Trail Firearms" in Edmonton when they were closing out. I'm not sure if US customs will allow ammo to be shipped across the line or not. I do know for certain that I absolutely can't ship from the US into Alberta. The main importer into this country was Century out of Montreal.

 

[James K]

Hi, aagiv,

That amount of case stretching is too much and I would have the gun checked for headspace. Also maybe bite the bullet and buy a box of Norma ammo and see how it works.

Jim