Protruding Primers 9.5 x 57 MS

[Frederik Badenhorst]

Hi

I'm hoping to pick the collective brain of the forum members!

I recently started reloading for a Mannlicher Schoenauer 1910 - 9.5 x 57 MS

I slowly started with a load of 41 gr of IMR 3031 that gave me about 1750fps and I increased the load by 1 gr of powder up to 44 gr which gave a velocity of 1945 fps
I use standard rifle primers and a 270gr RNSN .375" Woodleigh bullet
Bear in mind the gun in question is the rifle version with 24 " barrel and not the carbine

Every cartridge that came out of the gun had protruding primers with rounded edges and a ring on the neck and just below the shoulder of the cartridge

No signs of excessive pressure were noted ie Heavy recoil or a stiff bolt

So the question is - Is this a headspace problem or is this insufficient velocity not reseating the primer
The primers stand about 0.0022" proud

 

[ZG47]

Classic headspace issue. I cannot recall the breech-bolt details of your rifle (Friday evening after dinner here) BUT if you can put the bolt together without the mainspring, a correctly resized empty case should provide a small amount of resistance as you turn the bolt handle down. No resistance means excessive resizing!

 

[Russ-F]

The short answer is the protruding primer is likely to be due to too low a pressure. The effect may also be amplified but not in itself caused by having excessive headspace. The more the primer protrudes the more likely it is you’ve got excessive headspace as well as low pressure.

Even with excessive headspace ‘normal’ pressure would still force the case head back against the bolt face thus effectively reseating the primer (stretching the case as well resulting in short case life). Too low a pressure can’t do this.

I’ve experienced the effect once myself (albeit with less primer protrusion) with recommended ‘starting’ loads in a particular rifle which in my case had a very long freebore, (the headspace was minimal). The problem disappeared as the powder charge increased.

 

[7x57Joe]

The protruding primer issue has been addressed, simply back off the resizing die but, the problem at the other end, the neck, seems to be more of a problem. Is the case the correct length? If yes, then it looks as if the rifle is short chambered and the neck is being forced into the lead which will result in the very end of the case being smaller than the rest of the neck. It would help to make a chamber cast so you could find what you are dealing with.

 

[tarbe]

I would definitely do a chamber cast before loading any more ammo.

 

[Frederik Badenhorst]

Hi Guys

Thanks for all the valuable contributions

I really appreciate all the input!

 

[fourfive8]

+1 about the chamber cast.

 

[HWL]

Try a factory load and you will have a perfect primer....

There is no problem with the gun but your cases.

As far as I can see, your cases are reformed, probably from .30-06 ?

You have pushed the shoulder to far back,..... throw them away and try new one with correct shoulder position.


HWL (reloading 9,5x57 for 4 guns & over 40 years....)

 

[Frederik Badenhorst]

Brand new 9.5x57 MS Qual Cartridge brass at 44gr of IMR 3031

It sounds like that is a pretty standard load

 

[sestoppelman]

If the brass didn't have the rings when you loaded them, they shouldn't have them now. As suggested, cast the chamber and see what the true dimensions are and load from there. But it looks like headspace.

 

[HWL]

Brand new 9.5x57 MS Qual Cartridge brass at 44gr of IMR 3031

It sounds like that is a pretty standard load

Ok, You did not made all the mistakes I made......

Nontheless, I would fire a factory load, to see how this case looks like.

...same number on action and bolt?..... still the original barrel?

For the Mannlicher addicted,... a pic oft the rifle would be nice!


HWL

 

[Brian Rothhammer]

Hi



Every cartridge that came out of the gun had protruding primers with rounded edges and a ring on the neck and just below the shoulder of the cartridge

No signs of excessive pressure were noted ie Heavy recoil or a stiff bolt

So the question is - Is this a headspace problem or is this insufficient velocity not reseating the primer
The primers stand about 0.0022" proud

What ever happened with this? Did you 'slug' the bore? If so, did it show to have been rebored or was it within 9.5X57 specifications?

 

[bruce moulds]

do NOT fire this rifle until you establish the cause of excessive headspace.
this could be in the action, the chamber, or the brass.
22 thou is the least it could be, and could be more.
if a case fails due to thos there will be a lot of high pressre extremely hot gas going somewhere.
the rings on the front of the cases are another issue, not good also, but not as dangerous as the headspace.
bruce.

 

[Frederik Badenhorst]

Hi there!!

Currently in South Africa!

Didn’t have a chance to cast the chamber yet, my attention got deverted for a while by a Model B 9x57 Mauser Sporter.

When I get back I will cast the chamber and let you guys know what the outcome was

Rereading a bunch of posts on different forums seems to suggest that having headspace issues with the pre war Mannlicher Schönauers is common

Kind regards

 

[bruce moulds]

frederik,
most interesting that excess headspace is not uncommon.
it is also known that some mausers developed this due to the lugs setting back, even with military 7x57 ammo.
it is suspected that the lugs were not bearing evenly, and the one bearing set back until both lugd took the backthrust evenly.
there were even jokes about not having to lap the lugs for even bearing, when a few hot loads would do the same.
this is where fn mausers and later are superior to older ones.
even say a mkX has better metallurgy than some of the older ones and resist setback more.
could mannlichers have been blighted by a similar problem.
the setback was caused by soft steel, and was still safer than some 03 springfields and more noteably some enfield m17s, possibly eddystones, which were too hard and just shattered.
bruce.

 

[SJN]

Hi Frederik

I am a Mannlicher Schoenauer collector and reload for all of them. I have never experienced such excessive headspace as indicated by your pictures. I also suspect that your cases are not to speck. If you do have a factory cartridge, compare measurements especially the case length. To check headspace, see if you can chamber a round with a piece of paper between case head and bolt head. With a single sheet the bolt should close tight and with two sheets it should not close. This easy test will tell you what the problem is.

 

[Ed McGraw]

I just had a .375 Rimless Nitro Express (9.5x57 MS) built for me. I got to watch the Gunsmith fit the barrel and to feel the resistance of the headspace gage as I closed the bolt. The reamer I used is cut to C.I. P. specs as is the headspace gage and my reloading dies. I form my cases (30-06 Remington brass) by running them through a 35 Whelen full length sizing die. Then I opened the neck up to .375. Finally I ran them through my 400 Whelen full length sizing die. I then trimmed the cases to 2.35 in length. Then I ran the case into the .375 full length sizing die with the die touching the shell holder. All this left the shoulder well rounded and measuring .441 in diameter. When I test the formed case in the rifle there was no resistance at all when I closed the bolt. This concerned me.

I have always wanted my cases to have some resistance when I tested them in the rifle.

So, I backed the sizing die out and I place a .030 feeler gauge between the die and the shell holder. I then ran a case through the die. The bolt would not close on the cartridge. I adjusted the die on a .025 feeler gauge and tried again. No Joy! I continued this exercise .001 at a time until the bolt closed with resistance on the cartridge. In the end the bolt closed after the case was sized with the .022 feeler gauge between the die and the shell holder.

I measured the neck length of the formed case and it was .022 short of the case drawing I have. Not having a lot of options I loaded five cases using 46.5 grs of H4895 and a 235 gr Speer bullet, O.A.L. 2.968.

Went to the range, loaded it up and pulled the trigger. The rifle fired without any issues. The bolt lifted without any resistance and the case extracted easily. An inspection of the case revealed the primer was firmly seated in the primer pocket. The case was fully formed with sharp shoulders and visually it appeared that the neck was longer than it was before firing. Each of the five rounds reacted the same.

When I got home I measured the neck length and sure enough they matched the case drawing now.

So this is what I think is happening in your case. The shoulder measurement of my fire formed cases is .447. That is .006 larger than the formed cases (.441) when formed with the die touching the shell holder. Since the shoulder of the chamber tappers from .447 to .401 (diameter at the start of the neck) the smaller shoulder diameter of the formed does not contact the chamber until in your case the firing pin forces the loaded round .022 deeper into the chamber before the firing pin sets off the primer.

Factory ammo for is as rare as hen teeth and the cost would be through the ceiling. Current production brass is most likely produced to C.I.P. specs. The chamber for your rifle is likely to have been made to fit the case drawing posted above.

If you are re-forming cases from 30-06 brass try the way I use. It might work for you too.

Ed

 

[fourfive8]

Well that's been over a year and no report back- hmmm? A chamber cast would be the best way to find out. Another way to proceed safely would be to load some new or fresh brass with hard cast bullets over a mid range load of 5744 seated well out and jammed into the lands when chambered. That would fire form that brass to that chamber. Then adjust the sizing die accordingly.

After looking at the photos again, I doubt those primers were only .0022" proud as was listed in the OP- look a tad more than that-much too much actually. A backed out primer after firing usually reveals excess headspace. But is only revealed if the load pressure was fairly low to moderate and not near normal working pressure. But to understand the after-shot signs and consequences of excess headspace and how it really works, requires the full understanding of the mechanics and sequences that cause it.

At low to mid pressure, a backed out primer will remain backed out thus showing symptoms of excess headspace. The firing pin doesn't push the case forward very much. It's the detonation and impulse of the primer that simultaneously pushes the primer to the rear with the same force as it pushes the case forward. At a little higher pressure, the primer, if it backed out during firing, will be re-seated as the case stretches rearward and stops at the bolt face. A little higher pressure may show a flattened primer fully seated even though the pressure was within the normal operating range of the cartridge/rifle. The cycle of a primer being popped out then re-seated and flattened in the process may give a false indication of excess pressure.

A test for anyone with a cartridge design or re-loaded cartridge or rifle/cartridge combination that may have a question about a potential headspace issue, would be to load and fire a low pressure round with a cast bullet seated deep enough for some clearance between ogive and lands over a suitable powder like 5744. Need to stay below 20-30kpsi. Above that and the brass will stretch rearward, re-seat the primer and give a false indication there is NO headspace issue. Do this if you really want to find out about how much headspace control your particular rifle/cartridge has or doesn't have. If you don't want to find out then only shoot loads that are closer to full pressure- 30kpsi +.

 

[bruce moulds]

or to put it another way, use black powder.
bruce.

 

[Frederik Badenhorst]

Hi guys

Thanks for all the insights and advice, I must apologize for not updating this thread. To be honest , I have not had a chance to go and tackle the Mannlicher issue yet. Life happens and other things get in the way. The bottom line is that I need to do a chamber cast.
The primers were protruding 0.022” and not 0.0022” as originally posted.
The problem is most likely an headspace issue. I am not willing to get it rebarreled so the only real option is to fireform the brass by making a false shoulder so it headspaces on that shoulder. Looking into getting a Sinclair expanding die.

Interestingly enough , I had primers protrude(not to the same extent) on another batch of Quality Cartridge brass in 9x57 Mauser. Makes one wonder.

Cheers