Issue Reloading .25 ACP

[24-7 Dave]

While I have been reloading quite a few different pistol cartridges for many years, I just reloaded my first test batch of .25 ACP rounds ever and encountered a very strange case failure I've never seen before (see photo of single case below). I have fired at least 3 boxes of factory ammo through the firearm in recent years and never observed any case deformity whatsoever, so I am questioning my reloading and would like your advice before I move forward. Here is the data:
Pistol: Mauser Model 1910 (Yep, it's a real family oldie!)
Dies: New Lee Carbide dies
Cases: Once-fired FC (sized and wet tumbled with stainless steel pins, so brass was like new inside and out)
Bullets: 50 Grain Magtech FMJ RN
Powder: WIN 231
Primer: WSP
COL: 0.900 with a very slight crimp
Data Source: Lyman Pistol Handbook, 3rd Ed.
I loaded 10 rounds each with the following loads per the Lyman min - max range:
1.0 Gr.
1.1 Gr.
1.2 Gr.
1.3 Gr.
1.4 Gr.
The powder for every round was carefully trickled into the pan of a balance beam scale since the weights are so miniscule. The badly deformed case was in the batch of 1.3 Gr. rounds--the load which actually gave me the best, tight grouping at 10 yards. Out of 50 rounds loaded and tested, it is the only one that was clearly deformed.
In the second photo below, I placed two other cases from the batch of 1.3 Gr. test rounds beside the deformed round for comparison, and to the right of it is a RP factory round that I fired as part of my reference group. There appears to be very slight case swelling in the other two FC cases, as is the case of many of the 1.1 - 1.4 Gr. loads, although nothing more than the two examples shown here, while the 1.0 Gr. reloads and RP factory round show little or no swelling. I will also note that I ran into some ejection problems throughout the testing, but didn't notice the deformed case until I was picking up the empties and placing them back into the manufacturer's plastic ammo tray.
As for the firearm, I didn't notice any irregularities in the chamber walls when I cleaned it, so I am scratching my head over this and would like to hear from the experts before I attempt to reload any more rounds using either of the other powders I have on hand that Lyman recommends (700-X and Red Dot). FYI, I started with WIN 231 because the flakes are much finer and easier to trickle compared to the others.
Any advice/recommendations?
Thank you!
Dave

 

[Demi-human]

Did any reports sound louder than the others in a string? Did one have more recoil?

At first I thought extra pressure from bullet setback, but that case is bent crooked, not even fully chambered.

I am thinking that it was a Out Of Battery firing, judging by how far off center the pin strike is.
Luckily that much was in the chamber and the brass didn’t rupture.

Time to deep clean the heirloom.
It was able to fire without being fully closed. Some of the older firearms don’t have the mechanical safety interlocks today’s models have. The slide may have been just short of “in battery”.

Or the springs could use replacement.

Glad everything is okay.
Looks like 1.0 is the winner.
Since it functions and that is all that probably is needed?

 

[hdwhit]

I use 700X or Red Dot in my 25 ACP loadings.

I generally agree with Demi-Human.

I am curious about the fact the cases were expanded near the case mouth and not the case neck. Does your Walther's barrel cover the back of the cartridge?

 

[24-7 Dave]

Demi-human,
Thanks for the quick response and thoughts
To answer the questions:
- No reports/recoils were stronger than others. I ran into setback with my 1911 before the holidays and heard the variations in reports/recoil when I started loading RMR FMJs in thinner RP 45 ACP brass—that was my wake-up call. That’s why I was super careful with the powder measure and used just a little crimp when I started these test loads.
- I completely disassembled and deep cleaned the weapon when I got it from my father. The recoil spring was pretty stretched out so I ordered one from Numrich, which was better than the original, but it was also used and not pristine. Guess I’ll have to research sources for new springs.
- I tend to agree that it is entirely possible to fire out of battery based on the primitive design. This old Mauser is VERY basic (but does have a safety) —but that’s about all. The slide is only released by inserting the magazine and snapping it home to give you an idea of how simplistic the design is. It did have some problems feeding fresh rounds so you have me thinking it is entirely possible that it failed to go to battery once—which would explain the weird bulge in the case. So it’s back to the weak spring question…

 

[Jim Watson]

Wow, looks like a real OOB which is usually the ballistics version of "The dog ate my homework." What is the diameter of the case ahead of the ring bulge vs a normal case fired with that load?

Wolff lists recoil and magazine springs.
https://www.gunsprings.com/MAUSER/1910 & 1934/cID1/mID40/dID170

 

[tightgroup tiger]

You may want to check to see if your firing pin is a little sticky. That had to be an out of battery event.

 

[Akula69]

Agreed with above. I have purchased firing pins and spring sets from Numrich (for my model 20) and found them to be within spec...but its always safer to check.

 

[24-7 Dave]

All,
Thank you for the good information and recommendations. I will do a complete tear down and examine all parts for excessive wear and unusual wear or damage. Numrich only had used parts for this model when I ordered the spring and an extractor so I’ll check Wolff for a new spring - thanks for the link Jim!
I did measure the deformed case and compared it to the others and it was only slightly bigger compared to other fired cases from the case mouth up to the bulge (0.282 vice 0.277) and about the same as the others at the base (0.276). The diameter of the bulged section ran from 0.302 to 0.305, quite a bit larger than the chamber, so clearly it didn’t happen in the chamber proper. Now that I am cycling the action, I feel it dragging as it nears the battery position so I will completely disassemble it again to investigate further and replace whatever needs to go. Initially, I am seeing a slightly bent guide rod for the recoil spring, so it appears the incident did some damage after all.
Once I get this thing functioning smoothly I’ll test it with my remaining factory ammo and try some loads with 700-X and Red Dot and try to find out what it like best. It shoots surprisingly straight so I want to get it safe and reliable for the grandson to try out. Thanks again for all the advice!
Dave

 

[GeoDudeFlorida]

Well, the consensus is an OOB firing - and it may well be - but let's think about a couple of things, here:
The Mauser 1910/14/34 used a rotating bell lever disconnect. It's almost impossible for the sear to trip unless the slide is closed. That design was well known for decades for being safe and solid. It's the archetype for modern-day striker-fired pistols. Also, this is a blowback type firearm, not a locked-breech firearm; the slide is never locked to the barrel or frame. Firing out-of-battery is relative since it is designed to fire in an unlocked state. Next, this is a striker-fired control system. The striker is not fully charged by the firing pin spring until the slide is closed; however, it is possible for the firing pin to break or become lodged in the firing pin hole, or for a burr to be raised in the firing pin hole which catches debris. It's odd and atypical but not unheard of.

If this was an OOB event, in a blowback operated mechanism, it was more likely a high primer or a primer sitting on an object/obstruction in the primer cup - cleaning media, perhaps? - which was impacted by a section of the breech block on loading. It looks like it fired while still being extracted from the magazine (bent shape and mid-point expansion) half-way through feeding into the chamber. It's a testament to the strength and ingenious designs of these simple, antiquated, old, unsafe pocket pistols that they can take such abuse and not be damaged or even show any signs of mishap.

 

[Rule3]

Did any reports sound louder than the others in a string? Did one have more recoil?

At first I thought extra pressure from bullet setback, but that case is bent crooked, not even fully chambered.

I am thinking that it was a Out Of Battery firing, judging by how far off center the pin strike is.
Luckily that much was in the chamber and the brass didn’t rupture.

Time to deep clean the heirloom.
It was able to fire without being fully closed. Some of the older firearms don’t have the mechanical safety interlocks today’s models have. The slide may have been just short of “in battery”.

Or the springs could use replacement.

Glad everything is okay.
Looks like 1.0 is the winner.
Since it functions and that is all that probably is needed?

I agree with the above and my first thought was to replace the recoil spring AND magazine spring along with fp spring.
Sure looks like it fired halfway into battery, jut a WAG.

I always want one of those guns in 32 or 380. Just something cool looking about them.

 

[NorthBorder]

The rims on those compared to the RP factory round really looked to be chewed up, as in a lot of prior use. And the bulge appears to be where the base of the bullet is seated. And the brass appears to be pitted at the bulge. Could it be just a one time thing with that particular piece of brass, as in a weakened brass?

 

[Demi-human]

which was impacted by a section of the breech block on loading.

This warrants further investigation. Those are some gnarly rims. That primer does look a bit high. I’d like to see another picture of the strike to see what might have hit it. Whether the firing pin stuck or something was lodged in the breech face, something fired it before the slide was all the way closed, ha, or even close to it!

A perfect storm of a high primer dragging up the breech face and impacting a worn firing pin stuck part way out, igniting before chambering. And blowing right out of the chamber from a lack of friction, maybe not even touching the extractor.

Definitely have it repaired before the grandson gets to enjoy it, so that he can! Very cool.

 

[halfmoonclip]

A late buddy always compared reloading .25s to picking fly chit out of black pepper...
May God love you for doing it; .32 is as small as I go. Don't think Dillon even makes dies.
Let's hope it was a one-time shot; it does sound like you're taking all the prudent steps.
Sorry for butting in.
Moon

 

[24-7 Dave]

More great insight, thanks! Spring replacement sounds like a plan, so I just ordered the "Service Pack" spring kit from Wolff to replace all the key springs--only $16.72 with shipping, which is surprisingly cheap. The "Takedown Rod" is actually the part that I found with a slight bend, and it goes through the Recoil Spring Guide tube, but it's not in stock at Numrich so I won't try to straighten it myself since I don't have a spare, but hopefully it isn't impacting the spring guide.

 

[Rule3]

More great insight, thanks! Spring replacement sounds like a plan, so I just ordered the "Service Pack" spring kit from Wolff to replace all the key springs--only $16.72 with shipping, which is surprisingly cheap. The "Takedown Rod" is actually the part that I found with a slight bend, and it goes through the Recoil Spring Guide tube, but it's not in stock at Numrich so I won't try to straighten it myself since I don't have a spare, but hopefully it isn't impacting the spring guide.

Did you get magazine spring also?? If the mag is weak it can mess up the whole feeding and cause issues.
Any "new" to me old gun gets the springs replaced so I have a starting point if any issues,

Can you post some pics of the gun?? We love pictures!

 

[edwardware]

Any advice/recommendations?
Thank you!

That either fired out of battery, or was partially extracted too early under significant pressure. I suspect the second, and join @Demi-human in suspecting a flaccid recoil spring.

 

[GeoDudeFlorida]

That either fired out of battery, or was partially extracted too early under significant pressure. I suspect the second, and join @Demi-human in suspecting a flaccid recoil spring.

Don't they have pills for that now?

 

[Akula69]

and Here.We.Go.

 

[24-7 Dave]

Since it came up, I'm attaching a quick pic of the primers/bases of the reloads. All of the primers are actually flush and none are protruding. The deformed round is the second from the left on the top row.

Good catch on the magazine spring. I had ordered the spring pack on my phone and didn't get the drop-down for the Type II version that includes the mag spring so I called them and they updated the order to Type II. It only cost another $5 but well worth it.

 

[GeoDudeFlorida]

The deformed round is the second from the left on the top row.

It looks like several have off-center strikes and bulging around the firing pin hole.

 

[Demi-human]

It looks like several have off-center strikes and bulging around the firing pin hole.

But it does looks like the firing pin hit it.
Except the offending case lacks a firing pin hole indentation around the outside. Which is not surprising as it was not flush with the breech face at ignition. Maybe that this one was just the first one.

Hopefully new brass is in the cards.

 

[Blue68f100]

Some of the primers look like they have scrapes on them. Rubbing on the breach face...