Modern Historical Personal Defense Weapon Calibers 003: The 7.65x35mm MAS, a .300 Blackout in the 1940s?

7.65x35mmMAS

Since we’ve covered the two most prominent PDW rounds of today, I want to take a quick detour and look at an interesting – but obscure – personal defense weapon/assault rifle round from history. After World War II, the apparati of the German war machine were being dismantled, and anything of value claimed by the Allies as spoils. While the Americans got Germany’s most prominent rocket scientists, the French claimed Germany’s tank designers, and many of her small arms engineers. As France was looking to replace their motley and outdated collection of small arms (a suite which developed more organically than by design, thanks to two devastating World Wars), they put these German engineers to work, including one Dr. Heinrich Vollmer, who before and during the war worked at Mauser. Vollmer had been involved in development of – among various other projects – the StG-45 assault rifle, which possessed a unique roller-retarded blowback action that promised an inexpensive and reliable, yet lightweight weapon. This rifle would eventually lead to the G3, but during Vollmer’s stay in France, the French government set him to work making a smaller version of it, in variants chambered for .30 Carbine as well as a new round: The 7.65x35mm MAS.

An original 7.65x35mm MAS alongside its spiritual ancestor, the 7.92x33 Kurz. Image source: sturmgewehr.com

An original 7.65x35mm MAS alongside its spiritual ancestor, the 7.92×33 Kurz. Image source: Buddy Hinton, used with permission.

 

This round was intended to both fill the role of the .30 M1 Carbine when chambered for similar echelon weapons, as well as function as an assault rifle round like the 7.92x33mm Kurz, although the French at the time considered assault rifles to be special weapons, not universal ones as the Germans did.

Coincidentally, the 7.65x35mm MAS is also extremely similar to the modern .300 AAC Blackout. Bullet diameter and case length are virtually identical, while the case base is 1mm wider (10.6mm vs. 9.6mm), and the cartridge has greater taper. The primary difference, however, is the overall length (OAL). The designers of the 7.65x35mm were clearly influenced by the 7.92×33 Kurz, as the round sports an OAL of 48.2mm, almost identical to the latter, and much shorter than the .300 AAC Blackout’s 57.4mm OAL.

Ballistically, the 7.65x35mm is pretty unique, firing a very lightweight 93 gr (6 gram) projectile at modest muzzle velocity (2,350 ft/s, 720 m/s) from a short 13″ barrel. Based on empirical evaluations of the round, I calculated its boattailed bullet to have a G7 BC of 0.112, better than the .30 Carbine’s 0.190 G1 BC, but worse than the 7.92×33 Kurz’s 0.132 G7 BC:

cr6ACK0 QSO244r tP3E5gk

Weight-wise, the 7.65x35mm is very light for a full-caliber intermediate round, at a calculated 13.4 grams per shot with a brass case, based on SolidWorks models. This is lighter than the steel-cased 7.92×33’s 16.5 grams, and almost as light as .30 M1 Carbine’s 12.7 grams per shot.

What makes the 7.65x35mm MAS interesting to me, and why I included it, is that it represents a midpoint between modern personal defense weapon rounds and traditional full-caliber assault rifle rounds. The .30 Carbine before it certainly could also be considered to fill this space, but it uses a poorly-shaped round nosed bullet at very moderate velocity, and was designed for what today would be considered long barrel lengths, whereas the 7.65mm was designed for short (13″) barrels and uses a more modern spitzer bullet at a higher muzzle velocity.



Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He can be reached via email at nathaniel.f@staff.thefirearmblog.com.


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  • JustAHologram

    Wait are you not going to cover the .22 SCAMP?

    • Why wouldn’t I? I just had most of the work already done for this one, so I threw it together and posted it. 🙂

      • JustAHologram

        You have done most of these by type in groups, so when you jumped to this one it stood to reason we might be done with PDW rounds for a while.

        • ostiariusalpha

          Ha ha, Nate is just full of surprises.

  • snmp

    BTW the french have in 1918 : 8×32 mm SR (8mm lebel bulet with necking it down the .351 Winchester Self-Loading brass) for the Ribeyrolles 1918 automatic carbine

  • Tritro29

    Just when I was reading about the Greek 7.92×36.

  • Kivaari

    Wasn’t there also a series of Swiss rifles in a short 7.5mm cartridge. From memory I think I saw several rather modern looking rifles

    • There was. I have one of the rounds. Ballistically, they were very similar to 7.92×33 Kurz.

  • Mazryonh

    This is a very informative series of articles on ammunition you’re running here. Will you be looking into other speculative (i.e., never released to the civilan market) PDW calibers, such as .224 BOZ or the KAC-developed 6x35mm cartridge? .224 BOZ was a rather interesting concept that tried putting a 5.56mm AP projectile into a bottlenecked 10mm Auto case. It would have been interesting to see in ballistic gel tests.

  • George

    Need to consider something like this ish for 300 BLK replacement, too wide to chamber in a 5.56 chamber.

  • zardoz711

    Holy ogive, Batman!