Damaged Cartridge- opinions needed


I’ve been wanting a round of 5.2 x 68 Mondragon for quite a while, but never picked one up because the vast majority of the ones I’ve seen were badly corroded and expensive. I was afraid to pay the money to get a nicer one because I figured that it would just start deteriorating and I wouldn’t be able to do anything about it. I bought one today for a price too low to pass up that has the green stuff leaking from around the primer. Past experience tells me that this will get worse and spread. I normally pull the bullets and dump the power from rounds in this condition, but I’m afraid that if I did manage to get the bullet out without damaging the case (which I doubt would be possible) I don’t think I stand a chance of reseating the bullet without killing the whole thing. What would you guys do? I’m considering drilling a hole in the side to empty the contents and kill the primer. Are there any other options? Please see my other post about the bullet.


Well, its hard to advise you what to do with your own cartridge. Now don’t jump om me guys, because this is just my opinion. If you feel the cartridge must be cleaned out, I would drill the hole. Firstly, even if you manage to get the bullet out, it will destroy the whole bullet, and likely damage the neck and maybe even the shoulder of the case. Frankly, drilling a hole in the case damages nothing - not the bullet, not the neck of the case and not whatever neck crimp is there. You can be as careful as you want using an inertia bullet puller to take out a bullet, and I have done it often for one reason or another, but the crimp is never really the same again. Crimping is a feature of the cartridge like any other. Drilling a hole in the case destroys no “feature” of the cartridge. In the case of the Mondragon Piston Bullet, I don’t even know for sure how they put the bullet in the case. It strikes me that the case must have been necked after the bullet was inserted.

Frankly, if it were mine, I would find sometone who could section the entire cartridge, or at least neatly cut a very large observation hole in the side of the case, in the shape of an oval, not a circle, right up to the bottom of the shoulder, to show the nifty consturction of the bullet. Rather than being a poor, corroding specimen then, it would be a highly educational, “cool” addition to a collection. If you do have the cartridge sectioned, even if you chose to remove the primer which is probably one of the culprits to your corrosion, I would end the sectioning above the head, so as to preserve the entire headstamp. The headstamp “Polte Magdeburg” that is on these cartridgtes does not appear, as the sole entry, on many rounds. In my own collection - 7.9 x 57 and auto pistol, I have only one round that I can think of with this headstamp out of 22,000 specimens, and that is an aluminum-cased, steel-based Model 1888 7.9 x 57. That is, by the way, out of hundreds of Polte-made cartridges.

Well, that is just my opinion. Hope the guys who would never put a hole in the side of a case don’t get made at me for it!


John’s right. In this case you really have no choice. That primer must be “killed” and there is no way to get that bullet out without destroying the cartridge. I would drill, empty, and clean your round, but I would not section it until I found a worse one to section or one better than your first.
Just my opinion.


Jon - if you would drill a hole in the case anyway to dump the powder, why not make the hole a “window” to see the inside of the cartridge, especially the base of the bullet? Just wondered.


Until I had an extra, I wouldn’t risk damaging the bullet flange or tearing the case in two. I guess I’m just kind of a weenie that way.


My first encounter with this “before its time” cartridge was back in the 1960s, when I was just starting off in both cartridge and Arms collecting. An article in either “Guns” or “Guns & Ammo” about an original M92 or 93 SIG made Straight Pull/ Auto-fire Bolt gun from Mexico “un poco decompuesto” (a bit stuffed up) and its strange cartridge set my mind thinking.

The cartridge was Loaded by ( as you correctly stated, JM) first canneluring a cylindrical case, then placing the Bullet in the card disc, and placing the lot onto the cannelure; This was followed by the Shouldering and necking of the case, followed by the crimp ( same system as the Cordite Loaded .303, but the 5,2 cartridge has an almost “Weatherby” look to the shoulder and body taper (virtually nil taper))

Any attempt to “pull the bullet” will destroy both the card disc and the neck crimp. And given the age ( and the fact that the neck area may have been annealled before “necking”, it certainly was NOT annealed after Loading.

So the brass will be suffering from stress-induced liability to season cracking, if it has not already done so. (Work hardening).

The Primer “Leakage” is common in primers of this age ( and even younger)…it is due to the Potassium Chlorate content of the primer compound…this deliquesces (liquefies) in the presence of moisture (probably from breaking down Powder) and gives the characteristic White-Green “leak”.

The ONLY viable solution is to Drill (slowly) a hole in the side of the case ( start with a small ( about 1/16th) drill, using a Hand drill, and secure the cartridge case in a Vee Block. Use a small centre Punch to form a dimple in the case wall so that the drill doesn’t wander and ruin the rest of the case.
Once inside the case, take a 1/8 or 3/16 drill, and open up the hole ( again by hand). 3/16th (4,76mm) is sufficient to evacuate all the powder ( a Flake type typical of German “Gewehr Blattchen Pulver”,) even if caked by deterioration ( use a pick made of stainless steel or spring bronze wire to clear out all the stuck powder).

To clean the inside of the case of any corrosion, take some White (distilled) Vinegar, warm it, and using a large bore syringe, flush the inside of the case, leaving a small amount to stand in the bottom of the upright case over-night. This will wash out any priming compound left. Try not to “fill the case up” as this may damage the card wad holding the Bullet (“The Piston”).

Next, flush out the case with warm water, again carefully, and dry using a hair dryer. This will remove any remaining oxides etc. inside the case, and the drying out will help protect the Piston wad from further damage.

You may wish to get some Model Aircraft varnish and get some inside the case, to seal up both the card (factory varnished) and fill the Berdan Flash Holes in case there is still some compound there. Optional>

Outside, a brass brush can be used to remove the oxide from around the primer cup, (leaving a sort of Pink, de-zinced brass). This cannot be helped.

I would then varnish the entire case after a good clean with crocus cloth (NOT a High Polish, but Clean) with a good quality Clear poly-urethane varnish.
Place in cottonwool-lined little Box, and label accordingly.
This cartridge was made only in the period 1893-about 1908, and then only in relatively small numbers…the rifle did see extensive service in the Mexican Revolution, but by 1920, most of the Mondragon Piston Rifles had either been destroyed or lost, and their ammo used up.

Hope my notes are of help.

regards, Doc AV
AV Ballistics.


Wow! Great info Guys. I appreciate all who responded. I’m glad I found out more about this before I pulled out the inertia puller!


Thanks again!