WeaponsMan: History of M9’s Pivoting Locking Block

Not quite old or obscure enough for our beloved Forgotten Weapons, the M9 handgun is still in service with the US Military, though the Army now has the Modular Handgun System RFP bids in (but will take at least a year to test and determine the winner).

With its modern service record, for better or worse, few have truly dug into the full history of its creation, specifically its locking block. Those looking at the handgun typically only note the open barrel design, which is highly unusual for handguns.

WeaponsMan has a great article up on the history of the pivoting block design. Originally patented by Beretta engineers in the 1950s, it was the culmination of a series of inspirations including the Walther P-38. In the article, WeaponsMan traces the roots of the base M9’s design all the way back to the 19th century, citing the various patents (and showing them, where possible).

barrel_beretta_photobar_1104_general mauser_locking_block_patent_sketch-768x935

The first inspiration was from the Feederle brothers who were the original developers of the Mauser 1896 pistol commonly known as “The Broomhandle”. From there, the brothers improved upon their base design and introduced a pivoting locking block in 1907, using short-recoil operation.


For the full story, check out WeaponsMan’s article here. 

*Title photo courtesy of Gem-Tech. 

Nathan S

One of TFB’s resident Jarheads, Nathan now works within the firearms industry. A consecutive Marine rifle and pistol expert, he enjoys local 3-gun, NFA, gunsmithing, MSR’s, & high-speed gear. Nathan has traveled to over 30 countries working with US DoD & foreign MoDs.

The above post is my opinion and does not reflect the views of any company or organization.


  • Lance

    Well Army chiefs don’t seem to like MHS and may choose a different path, hence the M-9 may be around longer than tacti coolers claim. Nothing wrong with the M-9 the issues that came from Iraq where due to cheap and cheaply made mags. And was poor Army training on pistol maintenance. Over time may come where we return to.45 ACP known as America’s. Pistl caliber. But if we stay with 9mm NATO the M-9 current or modernized will still do the job fine

    • Gregory

      It was my understanding that the magazines were not cheaply made but the government wanted cheaper magazines. The finish inside was not smooth enough because the government did not want to pay more for coated interiors that were smooth and slick.

      • GordonTrenchard

        Yep you have it right.

      • Pete Sheppard

        The parkerizing used worked flawlessly in other mags, including Check-Mate M14 and M1911 magazines, and with the M9 mags *until* exposed to the ‘moondust’ of Iraq. where it was trapped by the parkerizing and prevented cartridges from smoothly merging from the double-stack body to the single-stack feed lips of the mags. As you say, newer finishes solved the problem.

  • GordonTrenchard

    The general in charge just said but a bunch of Glocks. Well why buy Glocks when you can keep what you have. Nothing wrong with the M9 to justify billions on a secondary weapon system almost never used in combat. I would say if they want to look into a new rifle and caliber yes go ahead and do that.

    • Rusty S.

      Nothing wrong…except cracked slides and locking blocks. I carried one on the job and fully aware of its shortcomings

      • GordonTrenchard

        In my opinion having owned Glocks there are shortcomings to those too. There will be some different but similar problem with them if adopted. My gut is cracked polymer frames will be the big one. You know like some GI trying to use the pistol as a hammer or using lighter on it to see if it will burn.

  • Strongarm

    Well, it seems WeaponsMan forgot to mention that; Nickl’s prototype was of inertia operated rather than recoil, and there were another rather older sample using this principle before P38; Japonese Nambu 94.

  • DW

    There’s got to be a reason why model 96 never seem to catch on like other .40SW handguns, I’ve read some sources say the locking block operation makes recoil “too sharp” compared to Browning design.
    …and yet Hi-point proves even the 10mm can be had in a blowback handgun, so I have no idea if that is true or even close to it.