Engineer's Delight: Stemple 76/45 Becomes the Stemple Takedown Gun

hey guys thanks for tuning in to another video on forgottenweapons.com i'm ian mccollum and i'm here today at the shooters outpost museum in hooksett new hampshire taking a look at a couple of pretty cool submachine guns these are basically modern era commercial civilian recreational submachine guns which is a concept that some of you in the audience are going to find a little bit baffling i think is a fantastic concept but what's really interesting to me is these are two guns that are made with distinctly different choices and different priorities in their design and execution and that's something that's an interesting aspect of firearms design across all eras you can often once you understand why a gun was being made what its purpose is that will often explain a lot of the choices made in its design and manufacturing and i think what we have here is a fantastic example of two guns that are legally the same thing but put together with dramatically different uh priorities so we'll start over here this is a john stemple model 76-45 john stemple uh was a gunsmith manufacturer he's born in 1949 uh father served in the military stemple kind of bounced around much of the world as a young kid as his father was stationed in various different places uh ended up coming back to the u.s growing up became a real gun guy especially fascinated with machine guns who doesn't like machine guns but there are some people especially talking 60s 70s 80s who are particularly into machine guns it was a relatively small community at the time and stemple decided to get into his own manufacturing as well and designed his own copy of essentially the swedish m45 or smith wesson 76 but chambered for the 45 automatic cartridge using m3 grease gun magazines hence the designation of this 76-45 the 45 doesn't refer to caliber it refers to the swedish m45 or carl gustav submachine gun which is the direct inspiration for the smith wesson 76 so this is prior to 1986 so machine guns can be legally manufactured and registered new in the united states and stemple comes up with this design uh cheap easy to shoot fun 45 caliber the thing with the original smith 76s and swedish car gustavs is they're all nine millimeter and well that's not very american it ought to be 45 so we'll build it in 45. and a critical element to the story here is before 1986 when the machine gun registry in the united states was closed stemple built and registered about 2 000 of the receiver tubes for this gun now 1986 comes and goes and stemple has this big stash of receivers and he's just slowly building guns and selling them uh never had a production facility really you know that was a sort of a hobbyist machinist just work by himself need hand assemble guns and frankly the quality on the original stimple 7645 is shall we say lackluster at best it's a pretty darn crude gun these were designed in an era when cost was really a huge factor what you really all you were really trying to do is get something that could dump rounds downrange and the durability wasn't really that big a deal you could still register new machine guns so there wasn't this huge value on the machine gun registration the receiver and the paper status of the gun that there is now because if something broke well you just make a new one yes there's a transfer tax but if you're a manufacturer like stemple was you don't have to pay the transfer tax and make a new one no big deal so let's proceed forward a few years uh stempel gets in trouble with the law uh i don't know the exact details i think it was an element of stemple was selling these parts and some other people were selling these other parts and if you bought all the parts from all the people you could assemble a machine gun where the feds claimed you could and so the feds went after people for conspiracy to sell illegal machine guns this goes to court for a number of years stemple gives up his manufacturing license this is another critical element and when he does he has to dispose of his inventory of machine guns now stemple would actually eventually not be convicted of anything but while he's fighting this it's hard to fight the federal government in court he gives up his license and he works at a deal with a close friend he transfers all of the guns all of the stempled tubes uh to his close friend with the arrangement of well you keep manufacturing the guns and selling them and pay me this being the firearms industry in the u.s which is notoriously not great sometimes this deal kind of falls apart because stemple's buddy does two of the three things he does keep building the guns and he does keep selling them but he decides well maybe i just i don't really need to pay stemple i have legal possession of these tubes uh they're registered to me now i can do whatever i want and he has no recourse so uh stempel having dealt with these federal charges which ultimately don't come to anything he's not convicted uh he then goes back and tries to get the receivers back from his close friend who declines to give them back and this results in a protracted 10-year legal battle over what is at this point about 1200 registered receivers and again this is post-1986 so now the fact that these are registered receivers is becoming more and more significant because you cannot make transferable new machine guns anymore as this process is continuing by about 2000 stemple meets a guy named brian polling who has background in manufacturing and and they become friends and lo and behold in 2003 2004 the lawsuit between stemple and his former friend uh is resolved there's a settlement and stempel ends up with something like 900 or a thousand of his receiver tubes back well now it's 2000 transferable machine gun prices have gone up quite a lot and there's an opportunity here uh but it's been 10 years stemple was never really mass producing never mass producing stuff in the first place and he approaches polling about hey would you like to make the parts for these guns and talking between them the two get some ideas about how they can improve the quality of the guns because where something like this was all well and good in the mid 1980s there's there are better things that you can do with those receivers and polling looks at this from a totally different perspective to him now the important thing is how do we do something that makes the gun uh more shootable more enjoyable um what do we do to make this a recreational commodity product that people are going to want to buy because they're going to want to have fun with it there's no historical aspect to a stemple 7645 so this gun isn't going to be competing on a you know collectors are not going to be buying them you can't really compete with an mp40 or an uzi in terms of historical authenticity instead it's a gun that you are selling for people who want to have fun shooting machine guns recreationally at the range so what may what's important to that market and uh we comes up with a number of things like well can it feed from drums because if it can feed from drums you have a much higher ammunition capacity you can shoot a lot longer and frankly it's just a lot more fun to shoot from a 71 round drum than 20 or 30 round stick mag and then well okay but we have legal issues here because if we're going to change up the design we have to be very careful about how atf handles this sort of thing you can't necessarily just change a machine gun because it's registered as a thing and it has to remain that thing so uh polling comes up or the two of them collaboratively it's a little unclear i suspect polling had a major influence in this in with the concept of the stemple takedown gun and the idea here is what can we do that both protects the receiver from any potential damage because if you destroy a machine gun receiver post 1986 you're screwed um the gun is destroyed and gone and you can't replace it and then how do we make it fun at the range and you know what makes it fun at the range being able to easily shoot control recoil hit your target and have a lot of volume of fire and so this is pretty much the first version is the first version of what becomes known as the stg 76 the stemple takedown gun drum fed bipod supported it's got a shoulder stock and a pistol grip off of actually an hk or a setme it's a really fun range gun so let's take a look at this point at how the mechanics of this temple started out and what the stg 76 is so the original stempel 7645 feeds from modified grease gun mags they need a notch cut in the back the magazine to engage the bolt or the magazine latch there the markings are rather difficult to make out here but it does say 76.45 and then john stemple an address and the serial number most of the basic smith and lesson 76 configuration is here we have a very simple blowback operated system there is there are no safety mechanisms to this there's no second sear notch to prevent it from firing if dropped what you've got and you don't have it on all of them is a notch up here to drop the carry hand the bolt handle into that's your safety the rear sight is a fixed aperture there the front sight is literally just a bent piece of metal all the bits are welded together on this we've got a smith wesson 76 style side folding stock in order to open it up you've got this cap head screw there and a spring and you lift that up and then pivot it around and then it drops back in place the magazine release itself is actually another cap head screw i think you're you're starting to get the idea here for disassembly the barrel shroud is which is also the barrel nut is threaded on pull that off then you can pull the barrel out very simple thing there the bolt is held in place by this big cross pin i can pull that out and then we have a rear end cap with a little bit of a rubber pad for a buffer we have a big old recoil spring caulking handle and a bolt which these were either not heat treated at all or rather poorly heat treated like this was a very very low end manufacturing process here you can see some of the elements here like oh the original tube the the plug for the back of the tube didn't quite fit in the back after it had been parkerized so we'll just you know dremel it down a little bit there to get it to fit the fire control mechanism is very simple it's pull trigger sear drops there's no manual safety the original smith guns and the swedish guns did actually have safeties on them so really really simplistic gun but let's talk about a couple of the things that this gun has going for it what stemple actually manufactured and registered was just this like 13 inch long tube it's a relatively small diameter tube for a submachine gun that's about 1 3 16 in diameter but it has a relatively heavy wall thickness for its size so it's a pretty durable tube that's a good thing the tube had the charging handle slot cut in it had the ejection port cut in it and it had the magazine well cut in it but as originally manufactured and registered these parts were not welded on what stemple did was put he made 2000 tubes put them on a shelf and then he would grab them one at a time or a couple at a time and build them for customers and it was then that he would actually weld on all of the other bits and turn it into this gun so come 2004 when brp and brian poling get involved they don't have this they have just the tubes so you have this tube now by atf uh dictate you are not allowed to change the size shape or location of the cutouts in the tube and i do want to point out that this safety notch up here was actually not on the guns this was something that was added only on some of the guns after the fact when stemple manufactured them in this capacity so um you've got a hole back here that's in there you've got a charging handle slot you've got the ejection port you've got the magazine well so what can we do with this well what bowling looks at is he figures first off we want to make we want to do nothing to actually physically modify permanently modify the tubes so you'll notice we still have you've got your your rear plug uh here oh and i should point out there's also the hole in the tube for the sear which you can't see on this because the fire control group is sitting there in the way but that has to stay the same as well well right about the time this is happening which is 2004 or so uh the government of finland has surplused a massive number of suomi kp31 submachine guns and something like 10 000 parts kits came into the us that were priced for almost nothing because there wasn't a whole lot you could do with them but by very happy coincidence the swedish m45 has some design lineage to the kp-31 suomi the swedes you before they adopted the m45 they used the m37 which was essentially a swedish version of the suomi and a lot of things things like feed placement ejection port angle those things kind of carried over a bit tube diameter as well so what bowling realizes is that he can take suomi parts kits and get a lot of what he needs to make a new submachine gun this will be capable of feeding from suomi drums which is a big point in its favor for you know popularity people are gonna people like shooting drums so we can use drums he is able to take a suomi bolt and turn it down only minimally like ten thousandths of an inch and it will fit into this tube for his stemple receiver now there's a big question about the trunnion what do you do with the trunnion because on the original stemple guns the trunnion is welded in place here and that's how this is typically done on submachine guns but bowling doesn't want to weld trunnions in place because that's a permanent modification to the receiver so instead he comes up with an iterative system uh early on he actually gets atf approval to add two pinholes in in the receiver and makes his own trunnion slides it in and pins it in place and these can be removed so if anything goes wrong with the trunnion you can take it out alternatively if you want to use a different caliber say 762 tokarev or 45 acp instead of nine millimeter you can replace a trunnion with one that will fit one of those cartridges bowling uses the surplus suomi barrels that came with the parts kits that gives you a great nine millimeter barrel this was back at the time when surplus barrels could be imported now next question is how do you actually feed from the magazine we've got the barrel attached by way of our uh internal trunnion here pinned in place well on the original stemples magazine well welded in place we don't want to do that instead he looks to the sten or mp40 model of a magazine housing that slides over the receiver tube and locks in place originally done for manufacturing simplicity now it has the added benefit of being modular interchangeable and not permanently modified so uh for his original guns he takes those surplus suomi barrel shrouds cuts them off and makes his own essentially copy of the suomi magazine well uh you know this isn't an actual swami one because on the swami the barrel shroud itself is quick detach you can flip a lever here and take it off well there is no lever on the brp stemple version but this is dimensionally the same as the suomi magwell and now we can slide that presto right onto our receiver and now we have a magazine well we have a trunnion inside this will pin in place in a moment now we need a fire control group and well we've got these suomi fire control groups which are pretty good however there is a hitch in that geometrically they don't quite fit because the location of the seer hole in the stemple receivers isn't the same as the location of that hole in a suomi but we're using a suomi bolt and so the you know the location of all this has to match up and so there are modifications made to the trigger assembly to give it the right dimensional setup to use the existing sear holes so there's the trigger now what about a grip we want something that's going to be easily controllable easily shouldered a pistol grip would be really nice and so brp designs their own little milled aluminum trigger housing so we can slide this there and then another cheap and available parts kit set me's or hk91 so we can put a set me or hk grip on there now the original stemple guns had a large diameter recoil spring but because this is going to use an existing suomi bolt it will use a swami recoil spring as well which is small diameter to fit inside the bolt but that is still nicely compatible with the original stempled design for the receiver end cap so copy that make a little adapter to fit it to an hk91 or set me stock and then pin through that holds the housing in place and a second pin to hold the trigger group itself in place and then on these the early version of the gun these pins are then held in place essentially by a safety wire there we go that locks those in place go ahead and put our bolt in bolt handle same design as the original stemple so we have now on the suomi this hole has to be drilled by the way in the suomi bolt because on the swami the original design had a charging handle back here this of course has to use the existing holes in the stemple receiver so it gets a side charging handle we can put in place our end cap and recoil buffer and instead of just a pin we now have a large screw connected pin that pin acts as the last element to properly hold the round receiver tube in alignment and then we need some sights well we've got the rear sight from the suomi which is going to match up nicely with the front sight which is already out on the barrel shroud we can stick a little piece of picatinny rail out here so that people can put on a bipod uh is this strictly necessary for a submachine gun no uh however interestingly there were original versions of the suomi built with bipods on them it was a factory option as well as some other guns like the czech zk383 sort of the quote unquote heavy submachine gun with a bipod and it certainly makes it more fun to shoot and lay the thing down and really have good directed aimed fire so now we have a far more practical far more enjoyable far more durable and effective submachine gun than the original stemple 7645s and it has been done in a way that doesn't modify anything and leaves the gun interchangeable you can pull off the trunnion the barrel the bot stock the fire control group the site is in fact screwed in it's not welded in place and so this remains legal because it remains capable of being built into an original stemple 7645 not that you would want to but you could um and so the receiver remains legal what i find really interesting about this is all of the design characteristics all the design decisions have been made on the basis of what is going to make these guns durable so that we don't damage the receivers things like this added internal trunnion in a worst case scenario if you have a cartridge detonate out of battery you have a tremendous amount of metal thickness up here and the thing that's going to be damaged is actually the trunnion itself which is repairable and not a regulated item we have design decisions being made on the basis of what's going to be most enjoyable to shoot instead of just what's simplest to manufacture because there are far simpler ways to make this than this whole housing and setting this up to use suomi drums but it's those drums that are fun and make the gun a viable commercial proposition now i should mention that this dates to prior to 2008 this is probably about a 2006 2007 maybe done and today brp has exp has has developed this system uh several times over and they have a far more universal modular interchangeable system today but i thought this was a really cool example of the original early style of stg 76 that would lead to several more all right a couple other quick things i want to point out here that just roll back into this sort of all design considerations based on really the unique legal aspects of the machine gun market after 1986. so on the original stemple guns most of the markings are on the magazine well because that's welded onto the receiver it is integral to the receiver and that's acceptable however before the mag wells were installed in the guns the only marking that was on the tube was just j.r stemple grove port ohio and this was compliant in 1986 that was fine that's all you needed on the receiver tube at that point in its manufacture when it was registered brp brian polling however is concerned that those markings like maybe atf will change their mind because those markings don't meet standards in 2004 there's not enough information there the letters are too small they're not deep enough necessarily and so he has stimple actually go through and re-engrave all the receivers with an upgraded style of marking so this is basically this is the same information john r stemple grove port ohio however the model has been added and a serial number a much larger more readable serial number has been added to every one of the receivers so that's why you'll find original stemple 7645s with these really cheap difficult to read markings but all of the brp guns have this improved style of marking on them and then he's added his own markings here in fact it's funny the company is brp named after the guy who owns it on this he was setting this up as sort of the the stg which does technically stands for stemple takedown gun but of course we recognize that as sturmgere so there's a little fake off and up on it and he's written brp in the style of a german world war ii factory code which is kind of cool also worth pointing out in fact the sharp eyed will have already spotted it this stg is serial number 282 where this original stemple is serial number 1072. and the the explanation for this is actually fairly simple uh stemple serialized these things and stuck them all on a uh on a shelf by the way there's the the original serial number on the tube of this 7645 1072 these tubes all sat on a shelf and were just grabbed at random to build into guns and so there is no uh there's no significance between serial number and date of manufacture it's basically just random the stg76 is exactly the sort of gun that i picture coming out of various home building forums and project groups in the early 2000s you know this is the era of lots of interesting cheap parts kits and what can you kind of clutch together from one kit and another kit and we've got a suomi tube and a suomi site and we've got hk furniture on it on the back but to me while this is very iconic of the period this is only the beginning of the story because polling recognizes that what you can do with a an unmodified system it's like if like if you keep your bolt and receiver and recoil assembly system the same there can be a lot of modularity involved in this like because you can't modify the receiver for legal reasons you're in a position where you can take advantage of that fact by offering a lot of other configurations so i'm going to do some videos coming up in the future looking at a couple of the other things that that brp working with stemple uh by the way stemple passed away in 2007 sadly but brp continues to work with the stemple family doing the same work providing still selling the guns and and coming up with really interesting alternative setups for them so we'll look at a couple of those other setups in future videos because this one has gone quite long enough already at any rate um hopefully you guys enjoyed the video thanks for watching and stay tuned for the follow-ups you

Channel: Forgotten Weapons

Views: 365,689

Rating: 4.9740109 out of 5

Keywords: history, development, mccollum, forgotten weapons, design, disassembly, stemple, machine gun, receiver, tube, transferrable, stg-76, brp, Brian poling, suomi, s&w 76, swedish m45, Swedish k, smg, submachine gun, ate, laws, legal, nfa, pre-86, post-86, hughes amendment, drum, bipod, zk383, modular, engineer, BRP Corp, stg-34k, stg-m1, stg-1928

Id: RlHzy2LtS4k

Length: 28min 49sec (1729 seconds)

Published: Fri Sep 17 2021