Hello Folks

I have a 7x57 Mauser 98 Model B sporting rifle from 1910 that takes a no-go gauge with aplomb !

I'd like to shoot it and know once I've got brass that is "adjusted" for the excess head-space all I need to do is watch the setting on the sizing die.

The question is how to get brass with the right shoulder and "un-stretched" in the fire place. Can I fire-form it ? The amazing "cream of wheat" is not available here, what else could I use.

Thanks

What caliber is your Mauser?

I would recommend that you get a datum line tube of some sort and check your chamber against loaded ammo and against the chamber drawings.

Just expand a few cases or use cases from a larger or longer round with the same head diameter. Size the cases until the bolt will just barely close with slight drag.

Check the head to shoulder length of the sized cases against what ever ammo, die or drawing you consider is standard.

The commercial tool to do this with is made by Hornady. I am sure any machinist or tool maker could find a bushing that would be suitable.

If you start with a new oiled case it will
stretch to fit the chamber without a stress
ring. No it won't increase chamber pressure.
Then adjust your die and enjoy.

Sorry should have mentioned its a 7x57 so I could progressively neck down some 8x57.

Hawkins, do you mean fire-form new oiled cases ?

Thanks

Yes you could check your shoulder position with 8X57 or cut down .30-06 or even fired .270 brass.

You can also make your hunting brass from those over length rounds or from 7X57 that has been expanded at the mouth and sized back to fit your chamber.

quote:

Originally posted by Tentman:
The question is how to get brass with the right shoulder and "un-stretched" in the fire place. Can I fire-form it ? The amazing "cream of wheat" is not available here, what else could I use.

Thanks

You take new 7x57 brass and create a "false shoulder" (more below) such that the case headspaces on the false shoulder. Then you just load and shoot as you would otherwise have done. Voila, no case stretch, and cases ready to be sized with the die set up for this particular chamber.

To create a false shoulder, neck up (new) 7x57 brass. Using new brass will ensure the lowest chance of loosing brass in the process. Very likely, you'll just need to neck up 1 caliber size - for your 7x57 use a .308 expander. You then have to verify that brass necked up such does NOT chamber in your rifle, and that this is because the neck now gets in the way... (If it does chamber, you'll have to neck up further until you have a necked up case where the neck will prevent the case from chambering). You now run the necked up brass into your 7x57 sizer, and gradually size the neck bit by bit - slowly turning the die into the press. When you have a sized case which will *just* chamber in your rifle, you have your brass with a false shoulder and are ready to go.

In principle you can also start with 8x57IS brass, but you'll end up with incorrectly headstamped brass.

- mike

First, congratulations on understanding that headspace is the relationship of the chamber's datum point to that of the brass. There is no such thing as a gun with "excessive headspace", just brass that is too short for its particular chamber.

The "false shoulder" method of headspacing for the initial firing is the best method. "Oiling" the chamber may or may not result in the desired results, and the "cream of wheat" method is pretty dicey (as well as messy). If you just HAVE TO HAVE brass with the proper headstamp, then expanding your 7x57 cases to .30 and resizing so that they just enter the chamber with a crush fit will work. Personally, I'd rather use 8x57 brass partially resized, but there's not a lot of difference in using either. Anything based on the .30-06 case will require significant trimming, but will also work.

One more method which will work in a pinch is to load your bullets seated out far enough that they tightly engage the lands, thus holding the case firmly against the bolt face (in other words, headspacing on the bullet). If you do this, use only "starting" loads since engaging the lands usually increases pressures to some extent. Some will argue that the force of the firing pin will push the case forward and you'll lose the advantage of headspacing on the bullet. I doubt this, but make sure you have ample neck tension, perhaps by crimping, to keep the bullet firmly in place against the force of the firing pin strike.

MHOs method works! I've used it.

When I get my sizer die set so that it makes the necked up brass fit the chamber ... I measure the distance between the bottom of the die and the top of the shell holder with feeler gauges so that I can reset the die properly when I make brass in the future.

quote:

congratulations on understanding that headspace is the relationship of the chamber's datum point to that of the brass. There is no such thing as a gun with "excessive headspace", just brass that is too short for its particular chamber.

And THAT'S the TRUTH!

Thanks Guys, I'll check out options tonight now that I have a few more ideas. I don't recall if I have any dies bigger than 7 mm (ok I know - who doesn't have a 30 cal in their gunroom).

The rifle is pretty old with quite a bit of freebore but could I load projectiles bckwards to get them to touch ?

quote:

Originally posted by Tentman:
The rifle is pretty old with quite a bit of freebore but could I load projectiles bckwards to get them to touch ?

Yes, in principle that will work. Although, as Stonecreek notes, you will have to watch out for pressure with this method. In the past, I have experienced cases not properly fireforming if loaded too lightly, though, so it is a bit of a balance to get it right.

Further to the option of using partially sized 8x57IS brass: in spite of the headstamp issue, using 8x57IS brass does have one potential advantage. Most (sporter) barrels have pretty ample chambers, necking down 8x57IS brass will leave you with brass with a thicker neck. This *might* be an advantage in terms of accuracy in a chamber with ample dimensions. Before you go down this path, though, you'll have to ensure the necked down 8x57IS brass will fit your chamber. Fire a factory 7x57 round in your chamber, measure ouside neck diameter - call this "dimension A". Neck down an 8x57IS case and seat a .284 cal bullet - measure neck diameter of case with bullet seated, call this "dimension B". For safety, dimension A - dimension B > .002" - and preferably at least .004-.005 for reliable operation under adverse conditions.

- mike

It should be noted here that all cartridge/ chamber combinations that have achieved industry standardization have specific dimensions and tolerances (allowable variations from standard dimensions). Among the specifications is headspace--both cartridge and chamber are assigned minimum and maximum dimensions for this parameter.

This means that there is, indeed, a maximum and minimum headspace dimension for std. caliber firearms (as well as ammunition). Chamber-to-cartridge clearance varies with changes in cartridge and chamber headspace, but both have headspace specifications that need to be held for successful and safe functioning.

Wildcats, of course, are another issue and brass must be formed--and subsequently reloaded-to dimensions that are compatible with the non-standard chamber.

Dave Manson

I'm sure you will want to have correctly headstamped cases so mho's false shoulder method is the way to go.
I have found though that if using the same case each time and winding the die down until getting the bolt to show just a touch resistance on closing on the case does not give the same effect to the next case which is sized in one go i.e. you invariably find that the second and subsequent case sizings with that die setting will produce cases with a tad too much shoulder set back. Preferable to use a different expanded neck case each time the die is screwed down a fraction. Once the shoulder 'headspacing' is reached doing this then you will get consistent sizing of your cases to match the chamber shoulder dimension. You can then neck up the trial cases again and run them into the die to correctly set the shoulders to the new dimension.

I have noticed this same effect when screwing down the bullet seating stem bit by bit to get to the wanted COAL where you think you have it just right but then the next bullet seated fully in one step will be just not quite where you want it.

quote:

I have a 7x57 Mauser 98 Model B sporting rifle from 1910 that takes a no-go gauge with aplomb !

He tells you what it is in the first sentence ! Why are you apologizing Trentman ?

quote:

Originally posted by Stonecreek:
First, congratulations on understanding that headspace is the relationship of the chamber's datum point to that of the brass. There is no such thing as a gun with "excessive headspace", just brass that is too short for its particular chamber.
.

Why do they make "GO" and "NO GO" gauges?

quote:

Originally posted by DManson:
This means that there is, indeed, a maximum and minimum headspace dimension for std. caliber firearms (as well as ammunition). Chamber-to-cartridge clearance varies with changes in cartridge and chamber headspace, but both have headspace specifications that need to be held for successful and safe functioning.

I understand the method for getting rid of the headspace, but isn't the fact that it exists telling you that there is something wrong with the gun?

How long can a guy continue to stretch his brass and use the rifle till either the brass fails or the action fails?

If you adjust the die you aren't stretching the brass.
Go/no go are relative to a standard chamber.
I doubt if you will ever get a seperation
with new un fired brass.
Actually Headspace is the distance between the case head and the breech face period.
People confuse headspace with the datum mearsurment. Cleveland is 500 miles west of New York but their locations are measured from Greenwitch England.

Hawkins is right technically and gives an excellent example, but headspace measurement for rimless cases is usually taken from the Datum line and is not necessarily an absolute number(actual measurement using a standard measureing tool like a ruler or a caliper), more like a "relative" number using any standard(gauge) for the difference in measurement amount...that's where it gets confusing to many.

Actually there are at least 3 and possibley 4 gauges for some military weapons...GO, NO-GO, FIELD and "WAR"(not sure if this is the correct nomenclature). Most gunsmiths use the GO, NO-GO gauges for fitting or checking for various reasons, most of which involve ecomonics.

"Something wrong" depends on many factors...a long chamber might be very wrong for a benchrest/target rifle, but for a military "hunter" all it means is you need to understand what is going on and HOW to best solve the "problem". I have many old military "stuff" I shoot and I didn't bother with using GO-NO-GO gauges...I just did the following procedure, and then went shooting.

I have a 338-06 with 0.022" "excess headspace" and once I found what the cause of the lack of case life, all I did was make a "horseshoe" shim to take up the space until Redding came out with their Competition Shell holders, then I bought those to correct any "excess" headspace. PLUS I always polish my sizer dies to fit the chamber so I don't get excess base sizing.

As long as I don't push the pressures up into the "mindless" realm I've gotten 40 plus reloads from ONE case, depending on straightwall or bottleneck cartridge, in chambers that have "excessive headspace" that has been "corrected".

Once I got the problem solved I made up 50 338-06 cases way back when and I'm still using those same cases after near 1000 rounds through the original barrel...mostly with 200-225gr Hornady SP bullets and a load of IMR4320 that produces slightly over 2700fs.

Considering the conditions most military weapons were produced, "in olden times" and today, it isn't any wonder the amount of headspace "excursions" that occure.

If I had that 7x57 Mauser rifle I would buy a set of Redding FL Type S bushing dies AND a set of Hornady headspace guages right off...THEN, seat a bullet of the weight you expect to shoot, "LONG", so it is firmly seated into the lands, over a beginning load of a medium burning powder(any one recommended for the bullet weight).

Make up at least 3 rounds...fire them...measure them...THEN...size one with a standard shell holder and measure it...the difference between the two measurements is the actual amount of headspace within a thou or two.

THEN...buy a Redding Competition shell holder at 2-3 thou less than the difference. Be sure to screw the dies down to touch the top of the shell holder, THEN, screw down another turn and a half...you need to take out ALL the flex and break over in your press otherwise you won't get full sizing and all the work you did is worthless.

I've been doing rifles, factory and my own builds, standard and wildcats and military like this for well over 45 years. I used to make my own guages but since Stoney, then Hornady came out with their guages I don't bother making guages for each rifle now...I just use "storebought" guages.

Once you understand that there IS a SAAMI or CIP standard and that there are many reasons why standards are not always followed, then you can begin to understand all the nuances that rifle chambers fit into.

It isn't right or wrong...it is reality..the way it actually is.

Luck

quote:

How long can a guy continue to stretch his brass and use the rifle till either the brass fails or the action fails?

The question is, "Why should a knowledgeable reloader 'continue to stretch his brass and use the rifle till either the brass fails or the action fails?" SAAMI's headspace specs ONLY matter if the ammo is made to the same standards. But. if the cases are simply sized to match the chamber there will be no more streching after the first firing. I've been reloading for two old surplus military rifles with 'excess headspace' for some 46 years without a head seperation. Nor have I needed to resort to any gimmicks like Redding's extra thick shell holders to do my sizing, just back the sizer itself off enough to do the job correctly, that's all anyone should need.

Those who agonize over 'head spaceing' off a belt or rim also miss the point. A competent reloader sizing ANY bottle neck case should simply adjust his sizer to match the fired case lengths at the shoulders and he's done all he needs to be concerned with.

Jim you are so right. A lot of this discussion is "pissin in the wind". Anyone want to know how much out of spec this chamber is? Well, use Scotch Tape! Just apply layers of Scotch Tape to the head of the case, keep "layering" until the bolt becomes hard to close, count the number of layers, and presto you'll know. BTW the tape is about .001 thick. Neck sizing is another method of eliminating "headspace" problems.

I realize that headspace goes away with each firing. Maybe I wasn't clear.

Given a piece of brass with a given case wall thickness above the web, there has to be a point of excess headspace that will stretch the brass so thin that it causes separations before the brass is fully formed to the chamber.

So if there is no such thing as a rifle with excessive headspace and there is no danger in firing said rifle as long as the brass used fits with no headspace, what does a guy do, just form his own cases from a different chambering that uses the same case that is longer?

The way I understand it headspace is a given measurement for each cartridge. If the headspace isn't correct, such as it easily gobbles up a NO Go gauge, then that isn't called excess headspace. It's called excess clearance. Headspace is only one set of numbers not a set of numbers that are larger or smaller then the specified headspace.

Now as far as the test gauges I'm aware of Go, No Go, Field, and Manufacturers Assembly gauge.

I agree with the many who replied to adjust your sizing dies to accommodate the excess clearance that you have. If using new brass I would expand it up then keep turning the sizer die down until it just chambers.

Oiling a new case and fire forming works fine. Just make sure that it is very lightly oiled - I just use an oily patch to wipe the rounds before firing.