Old 7x57 Mauser reloading

[Bob Thompson]

I have a nice early 7x57 Spanish Mauser redone sometime in the 50's or 60's with a sporter stock. I have acquired it at no cost and it shot well enough last weekend using usual precautions. It has somewhat excessive headspace according to SAAMI specs. (about .020) but it shot and only produced primers backing out about .010-.015. probably due to the headspace. Brass has miked normal after firing and the base is back to normal which by my manual is under the book spec. of .471. Mine mike .465. Federal 175G. The OA length grew just .001. from unfired cartridges. Sectioned brass pictured below. Doesn't seem to want to post a picture, but brass at head shows no stretching and brass wall thickness is normal and thick as in military brass.

My question is: do you think I could reload this brass. I would like to do some plinking loads using Chuck Hawks reduced load data with 4759 powder, 130 g. bullets @2055 fps and 46,500 cup.

And one last thing, what about some higher pressure factory loads with velocities around 2700-2800 fps. for hunting? Thanks much, Bob

 

[Bob Thompson]

Brass:

 

[publius]

I would take it to a good gunsmith, or better yet custom rifle builder and have them sign off on the safety of using it. If they say OK, I would try neck sizing the brass only and keep the velocities reasonable.

 

[Scorch]

If you have headspace issues, either neck size and keep the loads mild, as recommended above, or consider having it worked on to fix the issue. Factory loads are laoded so mild that you will not see stretching, you will likely just see primers back out, but that does not mean there is no risk.

 

[ThomasT]

Could you use a 7x57 forming die and make your brass from 30-06 brass with the die backed out a little so its slightly longer? Then your brass would fireform to the chamber without stretching the brass or backing out the primer. That would be my first thing to try.

You said you got the gun for nothing. How about having the barrel set back and rechambered? You would still have a low cost rifle in an excellent caliber. My favorite by the way.

 

[ThomasT]

I forgot about doing this to solve your headspace problem.

You can also expand the case neck with a .308 expander ball and then use your resizing die to resize the neck back down to 7mm a little at a time until the bolt will close with some effort and then install the bullet and powder and this will keep the case against the bolt face. That will fireform the cases to fit THAT chamber and should solve your problem with thinning webs on your brass. Be sure and use close to a starting load to make sure there is enough pressure to blow out the case. Reloader 15 is a good powder for this round and around 36-38grs is about correct with a 160-175gr bullet.

 

[sc928porsche]

My advice is to take it to a gunsmith and have the headspace reset. It would be well worth the effort and the cost. Remember, Safety is #1! Do youself a favor and dont risk the injury.

 

[ThomasT]

There is absolutly nothing that is unsafe in what I suggested. Your brass will fit that rifle only.

But like I said earlier I would have the barrel set back and rechambered just to avoid any confusion with ammo in case you have a second 7x57.

 

[44 AMP]

Along with the suggestions for forming brass to fit the chamber, remember that the old Spanish Mausers are only considered safe (when in good shape) for loads in the 45,000psi range. They are probably strong enough to take more, but who knows, with any individual rifle? The load you suggested is at the max end of what is considered safe, and you have a rifle that has excessive headspace. I wouldn't do it.

You should take the rifle to a good gunsmith, anyway. WHY does your rifle show excessive headspace? The three most usual causes are 1) the barrel has backed out (very unlikly), 2) the chamber has eroded (likely), the bolt has set back (also very likely).

Have the gun checked for chamber dimensions, AND bolt lug setback. Either or both together could be the cause of your excess headspace. The best thing to do in any event is get the rifle fixed, before shooting it further. What the best fix is depends on what is found, but get it fixed, so you don't get a face full of bolt someday.

 

[Bob Thompson]

Thanks much for all the fine suggestions guys. I have a few things to consider with the way the rifle shoots right now and wheather I want to spend the money required to take it to a gunsmith with the costs they are charging right now. I like the brass suggestions mostly as that would be the least costly and from my observations the bolt has set back causing the excessive headspace as military chambers are usually generous in chamber dimensions. Neck sizing would probably correct most of the problem and what I'll try first, then decide on what to do further.

With what I would have to spend at a gunsmith I could just buy a decent 7x57 newer rifle if that was my intent. Thanks again for the great info. Bob

 

[Paul B.]

Let's keep this simple. There is no need to go to a gunsmith Just set your sizing die to fit the brass to YOUR rifle. it's really quite simple. I set my dies up for all my rifles this way. If I have three rifles chambered to the same cartridge then I buy extra resizing dies for each individual rifle.

This is how I set up my sizing die for bottleneck cartridges.

1. Take a once fired factory round and blacken the neck and shoulders with a Magic Marker or Sharpee pen. Some people like to smoke the neck and shoulder, but I find the Magic Marker/Sharpee pen a bit better.

2. Carefully lubricate the case.

3. Loosen the lock ring on the sizing die and back off about two turns from when the die is set to touch the shell holder.

4. Size the case. Note where the marks are on the case and turn the die down about a half a turn and size again. Turn down some more, and resize again. What you are looking for is the marks on the blackening just touching the shoulder.

5. Clean the lube from the case and try it in the rifle. It may chamber just a bit on the snug side. If so, turn the die down ever so slightly, lube and size again. Wipe off the lube and try in the rifle. If it slides in as easily as a factory round, you should be good to go. If not, usually one more very slight adjustment should fix the problem.

6. Tighten the locking ring for the die and you're done. You have just set your sizing die up for a custom fit to your specific rifle, rather than a generic one size fits all guns.

Paul B.

 

[HiBC]

There are a number of ways to determine by measurement how much the shoulder is set back during the resizing operation.The dial caliper attachment (was Stoney Point,might be Hornady now) or the RCBS precision mic are two.
once the case is fireformed,it is true,we can compensate for headspace.
however,as 44AMP pointed out,what is the rest of the story?
If someone has been hotrodding M-98 2800 fps 150 gr loads through it,lug setback is possible.that can create cracks.As I recall,the 95s lack the safety lug and are not so good at gas control.
It is also possible,after the rifle was chambered,someone decided to lap in the lugs all weekend.
Could be the bolt was swapped out for a prettier handle.
If this bbl has a military type bbl fitup,it may not have a shoulder against the front of the receiver ring.It may just bottom against the diaphram inside the ring.Might be an easy fix.
Your gunsmith checkout is a good idea.

 

[Slamfire]

I have a nice early 7x57 Spanish Mauser redone sometime in the 50's or 60's with a sporter stock. I have acquired it at no cost and it shot well enough last weekend using usual precautions. It has somewhat excessive headspace according to SAAMI specs. (about .020) but it shot and only produced primers backing out about .010-.015. probably due to the headspace

Spanish Mausers, especially the M1916 Mausers, have a reputation for having "soft" receivers. Yours sounds like one of those.

I would not shoot the thing until I took the barrel off and examined the receiver locking seats and determined that the lugs were not setting back in the receiver.

 

[kraigwy]

Besides the safety issue, excessive headspace causes accuracy issues.

Ever wonder why target rifles have tight chambers?

It shouldn't cost much to set back the barrel.

Where did you get your numbers, or how did you measure your headspace?

what about some higher pressure factory loads with velocities around 2700-2800 fps. for hunting?

I vote "NO". Didn't you say your light loads back out primers?

Just my humble opinion, but I'm pretty fond of safety and I like chambers within specs.

 

[lefteyedom]

Having a barrel set-back is not a $300 job.

If the rifle doesn't have iron sights that have to be index it is a simple job.

If the Smith recrowns the barrel at the same time you basically have a brand new barrel.

Some Spanish Mauser are questionable but most are fine. Knowing if the rifle is one of the "safe Spanish Mauser" is worth the Smithy fee alone.

Would you drive a 1953 chevy truck that you just bought across the USA tomorrow with out having a good mechanic check it out first?

I am the founding member of $100 saddle on a $5 mule club. But a trip to a good gunsmith would be money well spent.

 

[hotcha45]

With your various suggestions, keep in mind that the primers are backed out, indicating, along w/the sectioned case, that the brass is not stretching to take up the headspace, so playing w/not sizing back to original dimensions will probably not work. Neck sizing will help, as with firings the brass should slowly stretch, but I'd vote for a trip to the gunsmith, as a soft receiver is likely.
I had this problem (excess headspace, not soft receiver) with the first commercial factory gun I ever bought, a Remmy 700 in '06. Once I realized what backed-out primers w/mild loads meant, a trip to a gunsmith was sickening as the bolt would just start a bit of resistance at .012" PLUS a no-go gauge. Remington told me that was at max but within their tolerance, so I had to pay to have the headspace set tight, and was the last Remmy rifle I have ever owned. Don't know if they still have such sloppy specs, but there isn't a good cure for it other than having the shoulder milled off until when the barrel is tight on the action the headspace is correct.