Cartridges of the Mondragon Rifle

The above cartridges were used in both the manual bolt action and the self-loading rifles. The 30-30 cartridge was only used in a single Model 1900 presentation rifle that was given to President Porfirio Diaz. This Mondragon model 1900 rifle, in 30-30 Winchester, resides in the Museo del Ejercito Mexicano, according to Mr Tanner, “Guns of the World” page 295.
5.2 x 68mm Mondragon
Since this rifle was being built by SIG, a Swiss arms company, it would make logical sense that Mondragon would seek out the famous Colonel Rubin, the famous Swiss cartridge inventor to design a cartridge specifically for the Mondragon rifle. The famous Colonel Rubin was the inventor of the 7.5 x 55 Swiss cartridge and the British .303 cartridge to name a couple.
This new 5.2 mm round was very high tech with super performance for a cartridge of the late 1800’s. Utilizing a rimless case, the bullet speed would be double that of black powder cartridges, 2900 fps vs 1400 fps. This cartridge was the 5.2mm series and was tested in several different calibers, lengths and loadings. Mondragon eventually settled on the 5.2 x 68mm for the manual breech loading bolt action guns. I have limited information about this round since I can only draw conclusions based on my personal collection of only 7 rounds and whatever info I can find in books. If you are interested in this cartridge look up “GUNS OF THE WORLD”, 1972, and the “MONDRAGON” article on page 286, by Mr. Hans Tanner.
The center bullet is a 5.5 x 68mm (.218″ caliber) it is flanked by two of the generally adopted 5.2 x 68mm (.208″ caliber) rounds. The case length for both rounds is 68mm, but the overall length of the 5.5mm cartridge is longer (I’m guessing it has the 105 gr bullet). The length of the 5.5 x 68mm cartridge is 79.6mm vs 77.2mm for the 5.2 x 68mm. The longer cartridge also has a sharper shoulder. I weighed the two cartridges for a comparison and found the longer 5.5 cartridge is 357 gr vs 350 gr.

What appears to be a very small bullet of .208 caliber, is actually a 1.2-inch-long projectile, weighing 90 grains, and seated very deeply into the case. Is the odd washer and bullet combination just for the bullets support because of the small neck surface area, or is there a “Colonel Rubin” secret? Does this “expanding chamber” concept reduce the chamber pressure during combustion and the gas expansion phase of firing? Perhaps a reader with a better understanding of the chamber combustion process will fill us in.




The projectile is a 90-grain jacketed bullet of .208 caliber and was launched at 2900 fps. That doesn’t sound like much compared to cartridges of today, but consider this, the current 5.56 NATO round fires a 62 grain bullet of .223 at about 3000 fps.
A flatter shooting cartridge requires less ballistic guesswork on the part of the average soldier, this makes the shooter less likely to miss because of the high trajectory of slower bullets. Also referred to as Point-Blank range.
See the following link for information about POINT BLANK https://en.wikipedia.org/wiki/Point-blank_range
The manufacturing and loading of this cartridge must have been rather problematic. As an avid reloader, I have tried to think through the sequence of making one of these complicated rounds. The method I came up with is to make this round out of a straight wall case, looking something like a rimless 45-70 or a .444 Marlin. First, add a primer to prevent the powder from falling out of the bottom through the primer flash hole. Add the powder. Crimp the case to prevent the washer/bullet combination from sliding to the bottom of the case. Mate the bullet/washer combination. Insert the bullet/washer on the case crimp and lastly form the neck and shoulder around the loaded cartridge. It would appear that this 5.2 x 68 brass case could only be used once, probably another reason why it was not adopted. by the military.
6.5mm Mondragon
The advent of smokeless powders in the late 1800’s initiated a radical series of new cartridges of smaller calibers. With Mondragon’s radical new gun design, a new cartridge was also needed. General Mondragon must have been so impressed by the new European small calibers such as the 6.5 x 55mm Swedish and the 6.5 x 54mm Mannlicher cartridges that he created his own. Mondragon’s first cartridge which was similar to the European versions was called the 6.5 x 53mm Mondragon. (It’s his gun, why can’t he call it that?)
The first bolt action Mondragon rifles used an 8 round, double stack en-bloc, clip for his 1890 and Model 1900 rifles. (I’ll bet you thought Mr Garand invented the en bloc! Actually, it was a Mannlicher invention.
Remember this is 1893!
6.5 Mondragon cartridge

(I finally found one!, this is a very rare cartridge. This one is 316.6 gr. and a bullet diameter of .266 in (6.7 mm) The 4 to the right were made at a machine shop and are solid brass with a 6.5 bullet.
7x57mm Mauser, 7.65 Argentine and the 7.5x55mm Swiss
The first two rounds (7×57 and 7.65) were specifically chosen for the South American market, these calibers were already popular south of the US border. The 7.5 x 55mm Swiss was for some trials guns tested by the Swiss Army and Air Force and designated the Model 1917.
You will find 99% of the Mondragon self-loading rifles in 7x57mm Mauser.
En-Bloc Clips
I have found two types of EN-BLOC clips used in the early Mondragon rifles, a small and a large. There may be more that I haven’t come across yet.

The small clip version on the left is an original Mondragon clip for the Breech Loading rifle. The clip on the right and in the gun on the right is a modified Garand clip. Yes! you heard right….a MODIFIED Garand clip. Only a few thousandths of an inch seem to separate them, probably just enough to keep the lawyers away from any patent infringement.
(The Mondragon version was first!)
Stripper Clips

The Model 1908 uses the standard 5 round Mauser stripper clips as found in the German rifles of the Great War and later.
On the right is 7mm Mauser stripper clip. Bottom left is 8mm Mauser stripper clip.
These stripper clips keep the rounds together for transportation and feeding the magazine, the rounds are pushed into the magazine and the clip is then discarded.