Colt MG38B, what is known and where is that info?

I am not sure you will find any more in print than what you already have, Richard. Nothing I know of at least. My understanding is that the C- prefix serial numbers designate commercial mfg from Colt's, as distinguished from U.S. military contract. I believe all the production for other countries are going to have that C- in the serial, though there may be exceptions. Those were considered commercial sales. The Colt's sales ledger in Dolf's Vol I shows sales to specific countries as well as to various aircraft makers who were also supplying product overseas.

Colt's seems to have updated the model name of the water cooled guns a number of times from the post-WWI period and into the 1930s. From what I have observed, MG38 water cooled guns were, at first, almost identical to what we know as the Argentine contract 1928s. I believe the Argentines contracted was merely the standard commercial Colt gun of the period, with perhaps minor differences for their specific needs. Caliber being one, of course, and it may be the rear sight graduations were caliber specific. But the general form of the rear sight I have seen on MG38s is much the same as the 1928s. At some point, a heavier water jacket was introduced. To go with that, there was a water circulation pump system, similar to what the .50 cal M2 guns had in U.S. service. I don't know what years the model names changed and such features were added. The MG38B version may have designated new features, but I don't know for certain.

First commercial model I know of was marked the 1919 water cooled, looking indistinguishable from the WWI U.S. 1917. The next variation I am aware of was the 1924. At some point, the new construction of the bottom plate came in, such as we see by the Argentine contract guns. I believe that remained the standard on commercial water cooled guns into WWII. I am not aware of any Colt manufactured guns with the WWII style bottom plates, except those converted by the Ordnance Dept from WWI stocks.

One other difference I have seen on some MG38s is that the Elevating Bracket is riveted to the bottom plate, rather than mounted by 4 screws as on the 1917s and 1928s. Another feature added at some point was the top latch with a "trigger" shaped lever that lifts the leaf spring for ease of operating the latch. It might be that old Colt's catalogs would be the best source to date the changes and revisions, if a range of years could be found to study. I don't think any books have covered the MG38 in depth, so we go by examples seen as much as anything else. There was a spade grip assembly made for these as well, and they are not very common. That would have required a unique trigger, I think. However, the major internal parts on these do not vary that much. I believe that the specs in place by the 1928 Argentine contract all included the captive drive spring, so that bolts would be specific to that feature from that point forward, distinguishing them from military bolts.

Also worth mentioning is a series of air cooled models that were intended for tanks I believe. I think these show up in the East Indies. I know of one in Australia, so they may have been sold to commonwealth forces for that region against the Japanese. These are shown in Dolf Vol I as well, and I think they were the MG38T and MG38BT, the distinction being one had the spade grips added. Key to this model is a very different receiver construction, with more rivets in the top and bottom plate assembly. Also, they have a trunnion mount adapter similar to aircraft Brownings. This same receiver was adopted by Uncle Sam only as the 1919 Aircraft gun, in about the mid 1920s, and did not serve long in our military. I've seen two examples of that, with the same receiver Colt sold as the MG38T/BT in air cooled config. Hope there is something useful here.

I have pics of an MG38 with Spades at the RIA Museum, pics taken by kkkriverrats after my camera batteries died. So we'll credit Charlie and the Museum for these. I've not seen inside, but outwardly they look identical in design to the ANM2 .30 cal spades. It may require a lever inside to reverse the internal trigger bar motion, such as is the case on Russ' Aircraft gun spades shown on his 1918 Aircraft Gun thread. The ANM2 bar from the trigger paddle pushes down on the bar in the lock frame, which then pushes the sear holder up, camming the sear horizontally to release the firing pin. The MG38 likely has a trigger bar that pulls the sear down, like a 1919 system. If so, there may be an extra component in the lock frame assembly to make it work. There was a set of MG38 spades at KCR a couple of years back, and I don't recall for certain who ended up with it. Will see if I can find out.

Pics added below.

Richard,
I've got a book showing a bunch of the Colt commercial guns. I think it is a reprint from the original 1930s book. It has some pictures and info on the MG38s. I'll get the title and see what useful info it has and let you know tomorrow.

I know someone who has one of the guns DLO . I'm not sure whether or not its one of the guns DLO brought in as a kit or not. I've heard he brought in a very small number of them, 3 or 4 maybe? They came from south america. I know Landies brought in a number of R75 part sets from down south and said there had been some MG38s he didn't get.

From the few guns I've actually had my hands on the grips are different in that all I've seen had spades. The grips are as Rolin noted, the same as the MG40/ ANM2. The topcover latch is a funky trigger looking piece sticking up at the rear and I think the backplate latch is more like the 50 cal or ANM2. I don't recall the trigger setup other than its a butterfly type. The receiver box is the same as the 1917 but the trunnion is a little different and the water connections on the jacket are like the MG52 watercooled. As far as I could see the MG38 uses the same waterhoses and maybe the pump as well. They didn't have standard steam hose fittings like the 1917, only the huge threaded fittings. I'll see if I can get in touch with an owner this weekend and get info or ask if I can give you his number....

Frank

Thank you for all the info and pictures!

Last night I spent quite a bit of time going thru my books on the Browning.
I read all the sections related directly to the Colt MG38 and the contracts and serial numbers.
The serial number indicates this was a part of the Dutch contract.
I learned a little about details of the Dutch guns.
I also leafed thru a lot of images looking for these guns on various mounts.
I noted in one of the images in Dolf's books that a MG38B is shown with a hole thru both side plates almost directly below the forward position of the charging handle.
The hole appears large enough for a pintle bolt, and I have seen this on more than one example of an MG38.
I would guess this was done so the gun could be used on a mount the Dutch already had in service.
Another picture showed Dutch East Indies troops with an MG38B on a Vickers tripod.
I wonder if the size and position of this hole would allow the gun to mount on a Schwarzlose tripod or perhaps a Colt 1895 "Digger" tripod?
I think the Dutch used both of those guns.
I need to look thru my secondary armaments book and see what is shown supporting an Colt MG38.

Richard

Screw thread Richard. Visually they appear to be the same as the WCM2 including the caps. I would bet they are interchangeable so the 50cal pump would work. The 50cal pump being to large and heavy I would have my doubts Colt only intended to accessorize the 50cal pump for the MG38 But possible. A smaller more portable pump and a second radiator tank would make it more ideal for a ground gun. I dont have those Colt manuals mentioned but would find them fascinating .
What I take away from the Colt Commercial sales were that that the ground guns were having a difficult time finding sales orders due to world economic disparity in general and it would seem that money spent was going towards newer tech and cutting edge tactics, and that was in aircraft development and ship building. That’s were Colt was doing very well. Infantry development lagged In parallel with trench warfare a tactic of the past.
If I get the chance next time, I’ll try and check the MG38 ports with the WCM2 hose set and try and screw them on so I can confirm this next time this gets asked.