doublegunshop.com - home Forums General Discussion Classic & Custom Single Barreled Sporting Rifles @ doublegunshop.com H. Barella 7x57 Mauser - Tight Chamber?

I'm looking for some help or insight into an issue I'm having with a recent rifle purchase, specifically what appears to be an ultra-tight chamber on a German commercial mauser.

As a way of background, I recently purchased a consecutive pair of H. Barella mauser rifles. I had been casually looking for a pre-war German commercial mauser, and jumped at the chance to bid on a two 1924-vintage H. Barella rifles that popped up on auctionarms. The two guns are consecutively serial numbered, with same dimensions, style, and weight, but in two different calibers - 6.5x54 MS and 7x57 mauser (or at least I think it is 7x57) - two of my favorites. The rifles have seen little use and are pretty minty. Below are a couple of photos of the guns:







I took possession of the guns a couple weeks back. The guns are really beautiful and the workmanship is everything I had hoped for, but like all "new" guns, I was eager to confirm all was well with a trip to the range.

I shot the 6.5x54 first and everything worked as expected, and the gun shot well. When I went to the 7x57, however, I immediately noticed the S&B 7x57 commercial ammunition was difficult to chamber. I had to put a lot of force on the bolt to get it to close. I should have stopped there, but was eager to shoot the gun so I pressed on. The gun fired just fine and the round landed right where it should have, but I couldn't fully raise the bolt handle. Not good.

Back at home, and without a fair amount of force, I was able to eject the spent cartridge. The primer looked fine (not flat), but I did notice some faint scaring on the body of the brass.

I then performed an extra thorough and detailed cleaning of the bolt and and chamber. While the guns cycles beautifully - very smooth and positive the whole time - when I attempted to chamber another S&B 7x57 round, I had the same issue; the round would not chamber and I was not going to force it. I triple-checked the ammunition as well as the markings on the gun to make sure I was not mixing up the guns. As you can see below, the gun is marked 7mm with a "57" under neath it.




My next thought was that I had an ammunition issue. So I tried another brand (Hornady) with the same result, much too tight. I knew it was time to get a cerrosafe cast of the chamber and see what was up.

I just got done measuring the casting. I can provide all the details, but what immediately struck me was the case body width. While the rest of the dimensions are pretty close, the chamber "width" is significantly smaller than the nominal 7x57 body dimensions (0.453" versus 0.472").

So now I am scratching my head. Do the gun's marking not indicate 7x57? Did I (and the seller) make a bad assumption on the caliber? Assuming he marks do indicate 7x57 as expected, why are the dimensions so tight? The gun is pretty minty, and I thought it unlikely to have been modified. But if it had been modified, the dimensions would not have shrunk. So what gives? Did Barella just make his chambers ultra-tight?

I welcome any answers, thoughts, or guesses. I feel like I am missing something obvious here, but I can't figure it out. Thanks.

Looking at the pictures, it seems like you have a nice problem. If the dimensions are correct, I'd call it a wildcat, and just handload for it.

Since you mentioned the rest of the dimensions are pretty close, I'd suspect that means all of it is not quite a 7mm Mauser. I wonder if someone thought it was a good idea to neck the 6.5 MS up to 7mm. I think it's amazing that the bolt closed on the factory round. I'd think a full length sizing die could be made from your chamber cast, plus a backup cast to verify. Then, I'd be highly confident that a standard 7mm Mauser seating die, maybe a Hornady, could take care of that step.

Only thoughts. Very nice looking pair. I'm glad you're interested in shooting them.

Quite a nice matched pair. I don't have any suggestions for you but I wonder why the original owner would want two rifles so close in caliber?

Good luck with searching out the solution. The custom sizing die sounds like the solution to me.

Use of a small base sizer die may cure the problem if it just barely fits now.

If they don't make one in 7x57,,I think 30-06 is available and would do (I think!) so as just to be able to swage down the bases a bit to function w/o difficulty.
You can always turn down the bases a couple .000. I've done them with nothing more than a sharp fine cut file, a couple swipes while the case is spinning in the drill press. It's not a drastic alteration.


Maybe Barrella used the 8x56MS case to make a 7x57 on. They have the very slightly smaller base dia but the rest is 'normal'.

Nice rifles!!

I think the problem is simply a slightly under-size chamber. I have a JP Sauer 30-06 that will chamber a factory round but no case resized after firing in another rifle. Eventually I found an ancient sizing die that was just enough smaller at the base. RCBS should have a small base die that would be worth trying. If not, I wouldn't hesitate to have a good barrel man run a proper reamer in and settle the matter once and for all. For a lark, you might try wrapping a layer of Scotch tape around the case at the tight spot and running it through you size die.

I believe the tough part here is that, if it's a rimless case chamber, the head of 7mm brass is probably .470"+. A small base die isn't likely to help wherever the shell holder stops the sizing die. Might also want to keep an eye out for where the shoulder ends up if one were to try running a case deeper into a die.

It may be easier to start with brass that has a head/rim size a bit closer to .453". A thought that I know can work is pushing a case all the way through a die, instead of retracting it. Maybe, there's a carbide pistol die laying around, like in .44 mag., that the top can be lopped off. I'd think it wouldn't take much to dig up something to use as a spacer on top of the reloading press ram to push a case past the carbide sizer insert. Only thoughts, I'd definitely try to get it shooting as is.

I know this may be Sacrilege but if it is a 7x57 why not just have a gunsmith run a finish reamer into the chamber to clean it up and be done with it???? It is not like you are changing the rifle is originally chambered in..
Wbldon

Ken,
Have you discussed these rifles on another forum? For some reason, your problem seems very familiar. The rifle was proofed in Suhl, and carries both a View Proof(crown U) and Definitive Proof(crown B).This shows the chamber dimensions were correct, at proof, for some cartridge that was for a bore(not groove)diameter of 7mm, with a case length of 57mm. This mark identifies dimensions and not the nominal cartridge. It is happenstance that the numbers match a well known cartridges name, not all do. The most common 7x57, is based on the M93 case, which has a normal head diameter of 12.05mm. There were some made for 7x57 cartridges based on the M88 case, which has a normal head diameter of 11.95mm. There is no way to know which was intended, from the proof marks alone( there is a similar case between the 8x57IR and 8x57R/360, except the proof marks don't match either name). A common 7x57 M93 cartridge made in Europe would be a tight fit in a chamber made for 7x57 M88. Depending on manufacturing tolerances, it may chamber with difficulty, or not at all. On the other hand, American factories often make 7x57 ammo on the 30-06 head diameter cases( even for 6.5x55 which is even larger), which is nominally the same as the M88. Therefore, if the rifle was chambered for the 7x57 M88, it is not surprising that S&B ammo would be difficult to chamber; and as for the Hornady, I believe someone else supplies their cases. If they come from Europe, they may also be M93 head diameter cases. I suggest you try Remington or Winchester ammunition. It is very difficult to make a chamber cast in a Mauser rifle, because of the gap between the rear of the barrel and the bolt face, as well as the cut for locking lugs. After installing a number of barrels in Mausers, I have learned this gap varies and may be .100-.120". Therefore a chamber cast will be shorter than the cartridge, so the measurements may not be at the same location on the case.
Another question you didn't address is the actual nominal caliber of the other rifle. There were actually two different 6.5x54 cartridges. One is the well known 6.5x54 Mannlicher-Schoenauer, and the other is the 6.5x54 Mauser. These are similar in performance, but very different cases. The Mannlicher-Schoenauer case head diameter is smaller than the Mauser's which is the M88 size. Consequently, depending on actual length, neck location, shoulder angle, etc.; it may be possible to chamber and fire a 6.5x54 Mannlicher-Schoenauer cartridge in a 6.5x54 Mauser chamber. It would be extremely rare to find a Mauser chambered for the Mannlicher-Schoenauer cartridge, or a Mannlicher-Schoenauer rifle, chambered for the Mauser cartridge. I suggest you closely check a case fired in your rifle, against an unfired one, to see if it has been fireformed to 6.5x54 Mauser body. I don't intend to insult you, but remember you should feed the Mauser rifles through the magazine. If you just drop a cartridge into the chamber, the bolt will close with great difficulty, if at all.
Mike

New unfired 7x57 brass measured in front of the extractor grove (all purchased >10 years ago).

Remington .4645"
Winchester .467"
Norma .4675"

Nice rifles. I would put up w/a bit of a problem if they were mine & attempt to keep them original. You might consult someone who makes custom dies to see if a small base die would size the head down enough & look for the brass with the smallest head diameter.

All,

Thank you for all the thoughts and insight - it is much appreciated. To answer a couple of the questions raised in the responses above:

1. I did feed the ammunition through the magazine (not dropped into the chamber singly). I haven't posted this problem on any of the other gun boards.

2. As Der Ami suggested, I did wonder whether the 6.5x54 rifle was chambered in the 6.5x54 Mauser cartridge, instead of the 6.5x54 MS cartridge, given that the rifle is a Mauser. The seller had the rifle listed as a 6.5x54 MS. I did peruse the nitroexpress forum, and it was stated that the bolt would not close if a person attempted to chamber a 6.5x54 MS in a 6.5x54 Mauser chamber (http://forums.gunboards.com/showthread.php?332929-Pre-war-mauser-oberndorf-model-98-type-m-6-5-x-54). The 6.5x54 MS round did chamber just fine, but I will go back and measure the fired brass. I was able to chamber and extract the 6.5x54 MS round with no issue when I shot the rifle.

Below are the photos of the "other" (6.5) rifle's proof marks:







My plan is now to make cerrosafe casts of both chambers. I'm going to redo the 7x57 to confirm what I got the first time. I'll post back with the results. I'm also going to measure all the various 7x57 commercial rounds I have on-hand to see how they compare. Thanks again for the help.