A look inside the Walther P38

I’ve already posted my P38 Anatomy image but let’s get a little deeper into this revolutionary German WWII classic.

The shortest possible story of the Walther P38 goes like this: Before WWI Walther was known for its high quality, blowback operated, small cartridge firearms.  During WWI it produced the popular Model 4 for the German military.  Post war the Treaty of Versailles forced Walther to stay at or below .32ACP.  This did not stop them from designing the amazing Walther PP and PPK pistols.  These used a great double/single action system with decocker that made them ideal for carry.  Attempts were made in secret to develop a 9mm Parabellum pistol for more lucrative military contracts.  The first attempt was an over-sized Model PP but blowback wasn’t cutting it.  Fritz Walther and Fritz Barthlemens solved this with their patented wedge-locking action.  A single/double action, wedge locking, hidden hammer pistol was submitted to the German authorities just before WWII.  They loved it but demanded an external hammer, which was provided shortly.  The rest is military history and explained in better detail back at C&Rsenal.

Now, a lot has been said about the trigger and safety on the P38, but let’s look closer at that wedge lock. It is attached and hinged under the barrel.  This wedge has two small lugs on either side, pointed upwards.  When raised, these lugs fit in matching channels cut in rails milled inside the slide, thus locking the barrel and slide together.  Also under the barrel is a sturdy floated pin, seated behind and with its dull spear-like tip pointing into the the wedge.  The wedge is held up by the shape of the inside of the pistol frame when at rest.

German Pistol Walther P38 Animation

Now, when we fire the P38, the barrel, slide, wedge, and pin travel rearward together in the locked position.  But, the inside of the frame soon opens up, allowing the wedge room to drop.  To make certain this happens the floated pin is positioned so that it will strike the vertical step in the frame first.  When it does it is driven forward as the block housing it collides and brings the barrel’s rearward travel to a halt.  The pin separates the rear of the wedge from the barrel, hinging it downward.  This lowers the locking lugs at its top, freeing the rails milled in the slide.  So the slide is free to continue with its momentum rearward, opening the breech.  Returned by the recoil springs, the slide reconnects with the barrel and shoves it forward.  As the front of the wedge is dragged along the inside of the frame it slopes upward, hinging it up, back into lock.  The wedge’s shape squeezes the floated pin rearward, resetting it as well.

That’s a whole lot of description for a simple operation that happens in the blink of the eye.  Of course there are many other operations in the gun considering the trigger, sear, hammer, safety, feeding, extraction, etc.  But we see those designs repeating on into a future of small arms design based on this very modern pistol.  I just wanted to take a moment and appreciate this unique locking action and I hope you all find it as fascinating as I do.


Othais is practically useless with modern firearms. That’s OK though, because he specializes in Curio and Relic military pieces and has agreed to decorate The Firearm Blog with a little history. He maintains his own site, C&Rsenal, with the help of his friends and the collector community.


  • I’m constantly amazed with the engineering that goes into firearms, especially the complexity of weapons designed so long ago. Thanks for this!

  • Pete

    Thank you, I had heard the P38 was unique but I never knew how it worked. The P38 is still the favorite nostalgia gun of many of us of a certain age…in no small part because the U.N. used the P38 as the base gun for the modular weapons system that they issued to their agents back in the 1960s.

    • Graham2

      I think you forgot the ‘C.L.E’ !

      • Lammo

        LOL. Definitely one of those “certain age” observations.

  • Plumbiphilious

    Thank you so very much for this article. I didn’t understand how the action worked since it’s not as popular as the Browning cam or straight blowback.

    You have legitimately helped me learn about this cool, cool little gun and I am thankful for it.

    I wish some modern pistols could use this. I’d like a non-straight-blowback pistol with a stationary(-ish) barrel.

    • Joshua

      Beretta M9, M9A1, and M9A3 are what you seek.

      The one thing I have to give the Beretta is that it is an exceptional shooter.

    • Blake
  • Blake

    awesome animation & article, thanks.

    (personal anecdote reposted from last year)

    My Dad inherited my uncle’s P38 when he passed away a few years ago. It came back with him after his Marshall Plan service, & it had pretty much been sitting in the back of his closet with two mags & the leather holster since then. Luckily it survived their house fire in the late ’90s unscathed.

    I got Dad a fresh set of Wolff gunsprings & magsprings for it, & dug up a manual on the ‘net. When we replaced the springs we did a full takedown & deep-cleaned & re-lubed everything.

    It runs like a top.

    We’re extra-careful to keep hot ammo far far away from it but it eats the cheap & dirty stuff like Wolf & Brown Bear all day long without complaining, & it’s easy to field-strip & clean once you’ve done it a few times & get the hang of it. The trigger has quite a bit of takeup but it breaks cleanly enough for a weapon mass-produced for military use 70 years ago. It’s not quite as accurate as our fixed-bbl CZ-83 but it’ll certainly hold its own against any of the other semi-auto pistols in the safe (& is better than several of them).

    It’s really cool that such an interesting piece of history (both world history & family history) can be enjoyed safely at the range, especially given that it had been stored for so long. Starts some nice conversations at the range too.

  • idahoguy101

    Beretta copied the P38 action and the FN P35 magazine to create their Model 92FS/M9.

    • Bal256

      No. Just… no.

  • Grindstone50k

    Is that similar to the lock used on the M9/92?

    • Joshua

      Yes, it is the exact same design philosophy. Though some changers were made of course, especially in the main spring.

  • Southpaw89

    Love these 3d animations of firearms operating, especially the unusual ones. Keep em’ coming!

  • LCON

    ALL Hail Lord Megatron!!

  • MPWS

    It is not “wedge” which would imply locking by friction on inclined plane but just simply – “swing link”.
    Interestingly, the same issue regarding integrity of frame where link engages which experienced U.S service M9 (Beretta 92) had Walther too. They had to extent considerable effort to eliminate the problem.

  • Zebra Dun

    As a kid in the fifties most folks who had pistols/revolvers toted some kind of .38 spl, those who did not carried either a .45 acp 1911A1 or a Walther P-38.
    The P-38 was quite popular around these parts .

  • Diver6106

    GREAT and simple analysis of the main mechanism. I own several P.38s of WWII vintage and enjoy shooting them – all steel! The post war P-1 versions started to cut cost – a sleeved barrel and alloy frame. The results is the frame cracked and they added a thru bolt to distribute stress and beefed up the slide making it ‘fatter’ but fortunately kept it steel. I also enjoy making parts guns out of WWII steel frames and P-1 fat slides, but you need to be careful about fitting parts and check they function and head space is within tolerance. See Walther Forums.

  • MIke

    The locking wedge looks like the one in my VZ-58 rifle, pretty cool