Hand-Fitted Parts Firsthand: French Modele 1874

We often hear the phrase “hand-fitted” in regards to either really finely made guns, or ones made before the the advent of truly interchangeable parts. Well, I recently had a firsthand experience with hand-fitted parts, and thought it would make an interesting video. i suspect a lot of people today don’t really think about just what that phrase implies, since we are so used to everything being a drop-in fit today.

Specifically, I have a French Mle 1874 officer’s revolver (and very cool gun, by the way), which was unfortunately deactivated at some point by having the tip of the firing pin ground off so that it could not fire. I, of course, want to put it back into usable condition, and so I was able to find a new hammer for it from Numrich. On initial fitting, I found that it was too tight against the frame of the revolver, so I ground it down until it fit nice and smoothly. And then, upon assembly I found that the sear engagement surfaces were far from interfacing in the proper manner with this replacement hammer. On a modern gun, a badly fitting replacement part might mean a lousy trigger pull – on this one it meant that the gun literally could not be cocked. A second replacement hammer (borrowed from another revolver as an experiment) fit better, but had so little single action sear engagement that the hammer could be pushed off the sear with just slight thumb pressure.

When you open up and old gun and see serial numbers on every single little part, this is why. Those critical close-fitting parts were made as a set, to work together with each other and not with any random replacements. We should take a moment to appreciate the massive improvements in industrial technology we have today that allow us to swap machine parts without a second thought!


  1. Original Austrian made Gasser 1870/1873/1874 were THE revolvers for that reason- loose tolerances, parts were probably 95% interchangeable… 🙂 Only thing that was hand-fitted with special care was a SA notch, but even there there is enough tolerance to make it non-issue. This leads to not the best triggers in the world OTOH…

    OFC, then there are Belgian made ones where everything was just slightly different, as on the video, and where two guns of the consequent serials will have +/- couple of millimeters difference…

    You really need to review Gasser family 🙂

  2. In my admittedly limited forays into the repair of vintage firearms it seems that replacement parts are all, if not outright oversized, then at the large end of the envelope. It appears that well into the 1930s it was assumed that you the shooter would have the good sense to take your firearm to Someone Who Knew What They Were Doing and they would hand fit by gradual reduction the new part. It seems that it wasn’t until WW11 that parts were intended to just drop in. For what it’s worth.

    Wafa Wafa, Wasara Wasara.

      • Ok, now seriously
        http://www.uh.edu/engines/epi1252.htm states that:
        was producing 10,000 muskets [with interchangeable parts] a year for Napoleon.
        Then, in 1806, the French government sacked the whole process. Why? By using unskilled labor, Blanc’s method had made manufacturers independent of government control over the old crafts. The government raised the arcane argument that workers who don’t function as a whole can’t produce harmonious products. They simply declared that Blanc’s method wasn’t working and they scrapped it.

        Declaring that something will not work even don’t testing looks strange to me. Maybe older fire-arms manufacturer paid for removing of new challenger?

      • OOPs. Sorry about that. That’s what happens when you try to post with less than five minutes left before you’ve absolutely got to stop typing and leave for work.

    • FWIW, this looks like a used part, not a replacement. Possibly buying a matched set of sear, trigger and hammer would help, but maybe not, as this hammer didn’t fit into the gun without some grinding.

  3. Aaron,
    I would simply take the original hammer plus one of the others to a qualified gunsmith and have the tip of the firing pin built back up by welding, and profiled. Quick and easy, plus it wont require additional fitting.
    Hey, I really enjoy the videos although often there is an issue with the sound.
    Good luck,
    Jim Oehl

    • Even simpler would be the Nonte method; face off the filed-off pin flat, drill it, and make a new firing pin tip from tool steel (such as drill rod) which is then fitted into the hole. If you do your measurements right, often the pin will drive in as a friction fit and not even need to be silver-soldered in place.

      As for changing collector value, that was rather degraded by the person who filed off the firing pin to begin with. At least this way, all parts and numbers still match.



  4. Good luck Ian, I hope you get it running again. I’ve had to do lots of hand fitting to a Chinese C96 that I own to get it working again.

  5. In the words of my grandfather, this is the difference in needing a gunsmith and a gun mechanic, which is what it called the “parts-changers” of his day. From experience in the past with original “un-fitted” parts from Dixie Gun Works that were intentionally made oversized to be fitted one-by-one to a gun needing repair, this is a specialized and tedious task. And after they were fitted, there was then the task of “case hardening” with the carbon or cyanide method … neither a trivial undertaking. It gives one an appreciation of the past craftsmen…

    • Given that tooling for making precise modifications down to the 1000th of an inch did not exist in the late 19th Century, gunsmiths were the best people to pay to fix any firearm you owned. Other would-be “mechanics” who failed to learn how to do maintenance without the benefits of modern day machining equipment or the gunsmith’s skills would end up with a non-functioning or exploded gun (and potentially a Darwin award to go with the latter).

      • While I truly enjoy most of your comments, as a history buff and a machinist, I think you need to do a bit of research as to when machining tolerances broke the 1/1000th repeat-ability threshold. Even smooth bore cannons of the US Military had a maximum “windage” of 0.010 prior to 1850 and Rifled ordinance had even tighter tolerances. Small arms could and was manufactured to very close tolerances in the Civil War. Indeed, by 1870 there were many machinists making firearms, who produced work on a regular basis with plus or minus 2/10,000ths and watch makers had been doing so for far longer. Even Newton’s reflector telescope had to be polished to within 1/4 of a wavelength of light

  6. my compliments on a well presented video on a subject I have discovered too: recent replacement of a Steyr 1912 safety.
    But, even more so, a look at your working collection as a backdrop. When are you going to do a “quick look at my collection” like was done by Eric of Moss Pawn? https://youtu.be/k7ZrdWKNJJ4

  7. One of more important terms I’ve learned from Forgotten Weapons is “tolerance stacking”. It explains and gives a name to why some of my projects just don’t work right. And is applicable to life in general. (Getting pretty philosophical here). Thanks Ian.

    I’m till waiting for the day I can use “fusee” in a conversation or apply it to something.

    • Well, other than a French term for a musket, that word also was used to describe a road flare, as well as a component of early spring-driven clocks. It was the vaguely conical-looking thingie that the cord ran around to regulate the clock’s speed as the mainspring unwound.

      So you’ve got some options.




    • Fusee is still used as a term by woodlands firefighters. It refers to a specialized road flare like device that drops burning material to ignite control burns. Looks just like a typical road flare.

  8. Yeah, at one level or another you will find that there is some fitting necessary in every firearm. All are different, individuals really. As you say, you may be able to drop parts into the trigger group of a modern weapon, but the trigger pull you get is a crap-shoot, might be great, might be crap, might be dangerous.

    My favorite common example of this is the Browning A-5 shotgun and its variants and copies. All the replacement parts come a bit oversize and this can lead to some rude surprises, like the gun going full auto. Fitting by a qualified gunsmith is highly recommended!

    BTW, you can use that old hammer, but you’d need to normalize the steel first, then shape it, then re-heat treat it. That would probably be a matter of case hardening the part, then drawing back just the head of the hammer. Be sure to tell your gunsmith if you’re planning to run a lot of ammo through the gun.

  9. I bought a replacement hammer for my Webley Mk IV; since even though it has a spur, it just won’t fire single action. It cocks alright, but when I press the trigger, it just rebounds without hitting the primer. Fires fine double action though.

    As for the replacment hammer; when installed, it’s so tight that I can’t even thumb it back to cock it… So talk about hand-fitting! Couldn’t be bothered, so I only fire the Webley double-action.

  10. Weapon of choice scenario:

    [heavy panting]

    Man, oh man. High command asked the team to take out that rogue “nuclear facility” and I lost the weapons canister when the enemy guards spotted me (the only gun I extracted before escaping was a drum-fed KP M/44). Now all we’ve got apart from the SMG are ten sticks of dynamite, 30 liters of nitroglycerin (!!), our side-arms, and the “broken” weapons in the safe house. Thankfully, the owner of that safe house is a gun smith. Fixing the safe house guns would be my best bet, but duct tape is not a solution! The alternative to this is doing a CQC grapple attack on a facility guard and taking everything in his possession (including his pants). Since the facility is now on high alert and hostages are still inside, don’t try an all out assault just yet. There also seems to be a “Metal Gear” undergoing test “walks” nearby…

    1. Carl Gustav M/45 BET (need to get this to fire real ammunition)
    2. AK-74 missing rear sight and butt stock (horrors!)
    3. crate of sturmgewehrs with sadly deformed receivers
    4. box of suppressed AMT Automag II’s with 6″ barrels (nobody wanted these)
    5. Wz.28 in need of a new bolt
    6. Schwarzlose MG 07/12 (needs a little fixing on the toggle)
    7. Type 97 Sniper Rifle with a scope that actually matches (same serial number)
    8. 7.5 cm kanon PL vz. 37 loaded with AP-T round
    9. Request a supply drop of your favorite toys (and run the risk of the bad guys finding the safe house)

    This activity is completely voluntary. You are not required to destroy giant bipedal nuke-launching tanks if you do not wish to do so. Please keep any and all criticism of this post humane and free of foul language.

    Thank you,


    • I rather fancy your KP44 9mm with the Suomi drum attached… And all I’ve got is this danged 16-ga. four barreled shotgun derringer/pepperbox! Oh dear… 🙂

    • “30 liters of nitroglycerin (!!)”
      At least it is no NI3 (substance even more prone to denotation than nitroglycerin)

    • Hmm… I think I can steal a few power cells from the facility, though I’ll need a large cardboard box for concealment. I’ve got 9x19mm tranquilizer dart rounds for the MK 22 Hush Puppy. You really don’t want to leave a blood trail, especially if the guards are trigger happy…

    • Other than it is mentioned in a movie, why in the world would you want only a 40 watt Plasma rifle. I mean 40 watts would be barely enough to melt through a old Gillette razor blade. If you really want a plasma rifle that would do useful damage in real world situations, I would go for 400 watts at a minimum power and no larger than 20 mm plasma bolt diameter at 300 meters. Too bad they are not man portable yet

    • As I recall the “Hush Puppy” was built on the old Smith and Wesson Model 39. Well I have a Model 59 that the addition of a slightly longer barrel and one of Hiram Percy Mazim’s precursor to the engine muffler could indeed make one.. sort of….Can…Do 🙂

      • The M59 was originally the MK22 Mod 1 “Hush Puppy”, follow-on to the original M39 (MK22 Mod 0). Basically an M39 with a newly-machined frame to take a double stack magazine; the first one was nothing more than two P-35 Browning magazines cut at two different points and the halves TIG-welded together.

        A few years later, Beretta did basically the same trick to create the prototype 15-round magazine for the first M92.

        Fun fact; Any 9 x 19mm P-35 can use Beretta M9 9mm magazines, simply by cutting an extra notch in the M9 magazine tube that matches the magazine catch on the P-35. This in no way prevents the magazine from still being used in the M9.

        Not only does this give you reload magazines for the P-35 with a +2 capacity, but considering that magazines for the M9 are made in 20, 25, and even 30-round sizes, this trick gives the petite’ Browning a fearsome firepower potential in CQB, exceeded only by some of the nastier SMGs.



        • In a really tight CQC scenario (and by this I mean grappling range) as opposed to ordinary CQB, isn’t the ideal equipment a pistol in one hand and a tough combat knife held reverse-grip style in the other hand? I saw this type of wielding style in the videogame Metal Gear Solid 3, where the emphasis on stealth and close-quarters take downs in most missions necessitated having both a melee weapon and a pistol at the ready (rifles with bayonets are not a good combination for a solo agent in enemy territory, especially inside the hangar of a prototype nuke-launching tank!). Of course, I was watching gameplay videos, not actually playing the game.

          If I’m wrong about this combat stance, please offer a better one.

  11. I know as a machinist that the proper way to restore your 1874 would be to machine out a new hammer piece or a new sear that works. But if you are very good at TIG welding, it is possible to cut off the head on the old hammer that had a sear engagement that worked (theoretically) and weld on the new firing pin section. Keep us posted as to your progress, it would be cool to see it firing again

  12. Ian,
    the proper way to check the differences between those hammers is to find a rod or shaft that fits the pivot hole correctly, and mount them together. Good bet for you would be a drill set, and find the best fitting base end (watch for burrs).

    Best would be an inspection pin set that steps up in .001″ increments. Keep an eye out for machine shop auctions, as sets missing a few pins go fairly cheap. That and “reference” marked sets. These pin sets are really handy for doing various things around guns. Sets that end at 1/4″ dia are the most useful. 1/4″-1/2″ sets are handy, but not used nearly as much.

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