Question about MK III STEN

[Seanpmc1]

Anybody know what era this thing came from?

Hard to see in the pic, but the magazine housing says STEN M.C. MKIII. The other side of the same part shows "LB" and a very light stamping that appears to be F13757. Magazine has "S.18" stamped on it, there is a "G" stamped into the end of the barrel-shroud, and "S32" on the "A" side of the selective fire switch.

Bore is in perfect condition other than some dust, but the breech-face shows signs of sand, or some other gritty substance being pounded into it by the bolt head.

I bought it about 10 years ago. The guy had several of them, each in seperate boxes, so I bought this one based on the fact that whoever "De-milled" it did so without getting into the barrel, and was careful to cut the reciever in a manner where it could easily be reattached.

Our Laws say I can reassemble it, as long as the barrel has a solid rod inserted and welded on both ends, and the Bolt is welded closed. Being a TIG welder and custom fabricator by trade, I can easily put it back together well enough to use as a display piece. The only part missing is the area of the reciever where the bolt-slot was located.

[Adrian Stevenson]

Hi Sean, it is a good WW2 issue Sten gun. This type was only made during the war.

Cheers, Ade.

[HJ-Collector]

what a gun very good

[Seanpmc1]

Thanks for clearing that up for me. The buttstock and the the barrel shroud was what I wasn't sure about. I know Hollywood isn't exactly known for being "period correct", but I think every WWII movie I have seen showed the "T" shaped butt and the shroud having vent holes all the way around instead of just at the bottom.

It was cut with a chop-saw and the barrel and Mag-reciever cuts match. I think I can square off the cut on the backside of the mag-reciever and use an appropriate length piece of tubing to replace the center section thats missing. I'll have to weld a strip of sheetmetal across the top to match the "fin" that runs down the top. I'm not to worried about all that because I do a lot of restaurant work and have the tools to refinish the welds and make them dissapear.

What I am worried about though is reproducing the finish. It doesn't really look like bluing, but its too shiney to be a phosphate finish. Looks like a cross between bluing and black paint. Hot Salt bluing will make a nearly black finish similar to whats on it, but I didn't think they were using that process in the 40's.

Anybody know what finishing process they used?

[Adrian Stevenson]

I forgot to add that the "LB" marking will most likely stand for "Lines Brothers" who were the main contractor for the Sten Mk III.

The MKIII is usually observed with the T shaped butt.

Cheers, Ade.

[Nige H]

Hi Sean,
The finish used depends on many things, some Stens are just painted, some are chemically blacked and some were just a hot oil oxide. As to caustic blacking salts these have been around for many years, in fact I think Colt started to use a hot caustic blueing process for commercial firearms sometime during the first quarter of the last century and certainly well before WWII. As to painted Sten guns, a special paint was used call Suncorite which was rich in zinc phosphate, this still made here in the U.K. by Trimite paints however its restricted in its availability due to its chemical composition. Again there is available "Sten gun" paint for restorers and re-builders of de-milled stens, which is a modern product designed to duplicate the original look. Most guy's in the States I've spoken to on the subject have Chemically blackened or phosphated there rebuilds, and then painted them afterwards, again this was a practice carried out during the war, so is authentic thing to do as part of a restoration.

BLACK GUN PAINT "BRITISH BLACK" GUN PAINT - 16oz Aerosol | AA-OK

Also you can obtain a 1-1 scale plan of the receiver tube, showing all of the areas requiring machining to make a new tube.

As to the Skeleton butt most of these went on Mk2 production, made at ether BSA, or at the Long Branch factory. As Ade stated the "T" Stock was normally standard for the MK 3 as seen in this period picture.



and here's a certain handsome chap with his Mk5S



Basically this Deac was a wreck when I first purchased it, no original finish and a lot of surface rust, it had also had manly layers of paint added over the years on top of the original finish and the rust. So it was stripped down and chemical blued to get this finish, and colour.

I've also built a Sten Mk1* from scratch with no original parts and this was given a blued/blackened finish and then spray painted Semi-gloss and then latter on full Matt black.

Heres a little bit more about it

https://www.warrelics.eu/forum/firea...-gun-mk1-7044/





Nige.

[Seanpmc1]

Thanks Nige. I've got the 1:1 wrap-around plan with all the prick-points marked for drilling. It also shows what sections have to be left intact. Here in the US, you have to leave the slot for the magazine partially blocked, and the slot for the sear has to be left entirely blocked. I don't see what difference it makes since they also require the barrel to be completely filled and welded on both ends.

I plan on using as much of the original tubing as possible, because I don't have any way to replace the original rivets. I will just weld a strip of metal across the Mag opening, and leave the new tubing uncut in the sear area. The manner in which this gun was de-milled will allow me to reassemble everything from the Mag-housing forward pretty easily. Since it will be a non-functioning gun, structural integrity won't make any difference.If hot-dip bluing was used back then, thats probably what I will do with it.

Kind of odd that you live in the birthplace of the STEN and couldn't get one in any better condition than what you described. The only rust anywhere on mine is at the breech-face, and its just surface rust. The Bluing on the lower reciever and the Mag-housing both look brand new, but the curved sheetmetal cover on bottom, and the fore-end of the barrel are worn to a light blue color.

It has an 1/8" hole drilled through the rib right behind the front sight that was obviously not done by the factory. I'm guessing somebody hooked a sling through the the extra hole and the back sight so they could carry it in a "ready" position.

[Seanpmc1]

Nige, I can't access your link for some reason.

Saying that I did try to reproduce the entire piece of tubing, how are you guys reproducing the round-headed rivets? Being a union sheet metal worker, I have access to the old style style rivets, and the punch and stake designed to use them. Sometimes we are called upon for restoration work that requires those rivets, but very rarely. 99% of the time we use pop-rivets.

Problem is, there is no way for me to get our tooling inside a piece of 1 1/2" tubing, much less get it all the way to the end of said tubing. When the Guns were made, they must have had some kind of special stake that would reach that deep, but still be rigid enough to take the force of the punch.

I suppose a piece of 1 1/4" solid shaft might work as an anvil/stake, but you still have the problem of getting the rivets into the hole from the inside and my fingers are too big to get through the barrel hole. Maybe their system was reversed from ours? Ours are flat on the back, inserted through the hole from the back side, then the punch forms the rounded head on the outside while the back is supported by the stake.

[Nige H]

Hi Sean
I didn't use rivets on my Mk1* build, I chose to use 3/16 UNF machine screws (I think if memory serves me correctly) and tapped all the holes in the areas where the rivets were required, the Mk1* has a round rivet with a flattened head/face and so this was easy to do, and once the bolt was in place they were filed to lose the slot and give the correct look. I'm sure you could do something similar and say fill the slot with weld, or if your going to paint your Sten III you could lead up the slot in the head of the machine screw with solder, plus then if you want to remove the screws at a latter date the leaded slots will be much easier to clean out. As to the link which one are you having trouble with.

Nige.

[Seanpmc1]

Hi Sean
I didn't use rivets on my Mk1* build, I chose to use 3/16 UNF machine screws

I didn't think about that. I could use round-headed Torx, or Allen screws then fill the hole with weld. That would be easier than filling a slotted head screw, and easier to finish it out without getting into the barrel shroud.

The solder would work with paint, but it wouldn't take the bluing if I go that route. Thats why most gunsmiths use the Rust-blueing method on side by side shotguns. The heat of hot dip bluing is enough to separate the solder joint between the barrels and sight rib.

Good idea, thanks.

(it was the bottom link, but I tried it again and it worked)