Inside the Chieftain's Hatch: Gun, Automatic, 40mm M1 (Bofors)

the 40 millimeter automatic gun was developed by October Leggett befores in the mid to late 1920s it was placed on the open market in 1931 and became a runaway success by 1939 it was in production in nineteen countries for US service so you got a backtrack two years to 1937 the US Navy got interested in the system and started trying to talk to before is about getting a couple for its own testing now unfortunately it failed due to some miscommunications come 1940 developments in Europe indicating you know maybe we'll better have another look at this and this time the US Navy also asked the army if it wanted to get involved as well because that way you had commonality of systems and it would make life so much easier army said yes so they set about trying to find one the Navy found a before is from the British Army in 1940 October the army well they got theirs from the same source in December of 1940 couplet has later they realized they liked it and in May of 1941 it was standardized as gun automatic 40 millimeter m1 on carriage m1 now all they had to do is get more than one so more negotiations were before is follow for local production American produced guns aren't exactly identical to those made overseas they're produced to american tolerances with national standard measurements so instead of millimeters for everything it is X of an inch and also these screws are a different size and so on however the important bits such as the caliber of the barrel or the interface they are standard and are completely interchangeable the Americans kept the metric designation much as they do for most weapon systems that are sourced from metric countries instead of calling it the one point five seven three inch or whatever it is still they wanted to change the carriage for American production methods so the axles became tubular the frame was welded the brakes became electric and so on this became the carriage m2 now there was a subsequent carriage the m2a1 but the only significant difference was the fact that when you cranked the Traverse handle you went around about three times as fast this is an early one it's an m2 and you'll see there's a couple of strange quirks with it although it is designated an m2 and thoughts of American manufacturer for some reason a lot of the instruction plates are in Swedish anyway I'm at the Rock Island auction company as I have been for a few videos now and yes they are auctioning a 40 millimeter before is if you wanted one for your home or garden anyway let's see what we can make of this there's no engines to talk about no Armour and well this would be quick the manual states that the 40 millimeter gun is for intermediate duties in between the heavy caliber guns of the three-inch and 90 millimeter class and of the calibre 0.5 it's a said that it is effective against dive bombers and low-flying targets and also states that it is effective against ground targets whoot as you can see it is in the traveling configuration so the first you want to do is remove the gun stay which for tanker world's it's the travel lock and it holds the gun basically over the rear as the vehicle is being towed it's held in place by two screws one on each side I may have to edit this this one might take a little bit more there we go let's see what happens okay now it's been unscrewed simply lift just a little bit free it up so don't forget to release a little locks down here on the axle and you can bring it down now this is also used as a point of leverage for twisting the axle to allow the frame the to descend onto the leveling jacks once the gun stay is down it is possible to traverse the system and fire without actually emplacing it earliest versions of the carriage had outriggers which folded in a little bit more and they actually blocked the Traverse of the platform a little bit but the later versions such as this come out a little bit further and you can have a full 360 degrees without interference and without having to take the axles away now this is as I say officially an m2 at least that is what the plate says on the side but there might have been a modification the original carriages for one turn of the Traverse handle will go about six degrees the m2a1 one turn of the Traverse handle would be 17 and 1/7 degrees so if you have an a.1 it'll take you ten turns of the handle to get from one side to the other if you have an m2 just regular without the a1 modification it will take you thirty turns of the handle well this looks like it's gonna only gonna take ten of course in traveling configuration there would be a top halt and covering the gun as a whole but there is also a cover on top of the feed rollers and simply lifts up and out of the way now the Rock Island auction company sells a lot of firearms this 40 millimeter is bigger than most particularly dangerous so you should never touch the ordnance if you do though never pull the operating handle to the rear like this never insert a four round clip of ammunition into the feed rollers here never return the operating handle back to the forward firing position never ensure that this cover is closed and never ensure that the external safety has gone from safe to automatic or single shot and never depress the operator's foot triggers here or at the rear here I'm sorry I had to do that I mean why else would you have a 40 millimeter before is in your back yard if not to do that sort of thing Ella onwards that's silliness out of the way let's get back to the carriage front and of course you have your drawbar which also performs the other half of the leverage forum placing this gun incidentally the gun crew is 14 personnel so when you're towing this thing you're probably doing it behind a Deuce and a half just they have somewhere to fit all the people as you can see the front wheels will steer easily enough of note the suspension is actually inside the axle so as the wheels go up and down there is a spring which compresses horizontally the brakes as mentioned are electric and the battery pack for them is meant along the central arm you run a cable to the prime mover and as you're driving along when if you have to stop you hit the brake pedal on the vehicle you also have to apply the brake by way of a separate control to the trailing carriage they're not just on/off it is a selectable level of braking of course the electric brakes aren't what you want to ordinarily rely on for long periods of time so there is a very simple manual hand brake on the rear axle one for each wheel the wheels come in one of two different types either this type which is the truck and bus wheel or the other one is the split rim combat type and the way you can tell the difference very quickly is that the combat wheels have holes in the disks or as your truck and bus don't tires are inflated to 45 psi of course on the outriggers and on the main arm you're going to find the leveling jacks now the manual is very specific when you are lowering the carriage and raising the wheels be cognizant of where your feet are so that they do not get crushed by the leveling jacks now I don't know if I need a manual to tell me that but okay once you have it down you can then crank away to level the carriage and of course you want the carriage to be as level as possible because that way you don't have to worry about counter correction it affects the accuracy of the gun if you can do it with Jack then so much the better once you have it in place then you can take these stakes they slot into a holder I guess you'll call it on the inside of the arm here you hammer that down and you should be stationary total set up time for the 14 man crew is supposedly 90 seconds so let's talk about the barrel there's two different types of barrel out there there's those of American manufacturer and those of Canadian or British manufacturer the US Army used both the giveaway is if you look at the recuperator spring if it's got a round cross-section it's American otherwise if it's square it's Commonwealth the guns were not identical the Commonwealth folks built they're going to the original specification completely metric the Americans know however all the important bits like the exact caliber of the barrel or the interrupted screw at the breech end where everything fits together they are absolutely identical so in effect there is no difference on the user end between a Commonwealth manufactured gun barrel and an American one there are 16 grooves in the barrel the twist is one in 45 at the breech end and one in 30 at the muzzle end also on the muzzle you see the flash hider and the lugs for the barrel range now the way you change out one of these things it takes four people person one is up top here and he releases the barrel locking mechanism that's what stops the barrel from twisting out of alignment and then falling off when you fire the next round two folks one on each side here have a support frame which notches into the barrel here and then you have the fourth guy on the barrel wrench he will rotate the barrel it will disconnect you slide it forward put it down let it cool off get your next barrel put it on the entire changing process is supposed to take 20 seconds of course the trick to rapid movement is a well balanced gun and as you can see this is very well balanced with just the one finger this is done by use of the equilibrator Springs there underneath here in these casings and they will be accessed from the front there are special tools of course because the springs are on the compression but if you do have to access them for maintenance this is how it's done as for the mechanics of the gun itself well firstly the rounds of percussion fired so when you depress the trigger and the plunger goes in the firing pin will physically strike the base of every round the ammunition comes in four round clips and you basically have loaders on each side feeding this thing alternately as fast as the cannon that way in theory you have a rate of fire of 120 rounds a minute can't go up 230 according to some people once the round is fired it gets ejected out hits the chute and then the momentum of the ejection is curved and it ejects the round forward in a nice little arc and you see one of these things firing you'll see 40 millimeter shell casings just go sailing through the air - kind of pretty to watch as I mentioned there is a selector between safe automatic and fire why these things are in Swedish I don't know elevation maximum elevation is a full 90 degrees maximum depression is 6 now when this thing is under power control there are cut offs at about 85 and 0 and the theory is that if you don't want to have the thing under power as it hits the stops so you get to 85 the power cuts off and then it kind of drifts of the last few degrees basic sight Errani around the computing so what you're doing is you're basically acting as a backup to the centralized direction system this is not a powered carriage the ones that we use with a centralized director and a generator they will be wired in together there will be a power system and the guns would simply slew wherever it was that the director was aiming them the crew simply became at home at Haun's feeding to the ammunition and in the event that the director went down then the crew would take over themselves as local control of course framing is a two-man affair you got one man is responsible for elevation of one man for azmuth and lead it's the same with the directors the directors also had two telescopes one elevation and one for azimuth for Amy ideally you want to be hooked up to a gun director in five that takes care of all the aiming for you and it's got a generator and it runs cables you're gone and you mount motor it's for the azimuth and elevation incidentally the manufacturer my old gear the same manufacturer that makes a best power Traverse is for the tanks like the m4 Sherman if you don't have the centralized director system then you can try computing site m7 which if you look at a telescope front sights it it looks very fancy for local control if you don't even have that then you have the simple m3 this is not even one of those this isn't in the manual that I looked at and I can only assume that this is an older gun that the manual sets out for and another giveaway is the slots in the breech casing these cooling slots were not there in later production unloading is a little bit annoying because these latches in the free tray only go one way so in order to get the rounds out again you have to insert basically an extractor it forces them out of the way you can then reach down and pull out the ammunition ammunition which is in the breech already well that comes out you have your course your operating handle when you crank it back the breech slides down vertically sliding and the KHL gets ejected out in the same manner as a regular shell casing would during firing of course this is an unfired ram so there is a bloke here whose job it is to catch this round as it comes flying out and to stop it going yonder to inspect the breech area well they got this nice little access cover in the top of the breech casing here and incidentally there's a plate that says build 1942 once you open it up you can access both the breech in the breech block you can also see this is the barrel lock which if you press here you'll see it this cannon gauges from the interrupted screw and you can then unscrew the barrel and away you go the manual states that after the gun has been fired while the barrel is still well you should rinse clean dry and oil and you do this every day until sweating ceases which is a chemical reaction of the burnt powder composition now if you really have to get the gun turned quickly and you don't want to wait for the guy to crank there is a faster method you pull up this handle that's above the cleaning staves and you simply pull the u.s. was never entirely satisfied with the fuses it was getting a foreign design so it actually developed its own it's a Navy few so it has a mark designation of course it wasn't very much in the air for the army to shoot at with its twenty eight and a half thousand the guns manufactured by Chrysler Oh incidentally they manufactured two barrels for each gun so instead of aiming upwards these things found service instead mainly aiming sideways a bit like this and you can imagine why the high-explosive rounds coming at year two a second is definitely gonna make a significant emotional event on you if you're a part of the Chinese wave common area in Korea nowadays of course these guns are long gone from US Army service they'll become relegated to being lawn ornaments scattered in amongst the gnomes in the pink flamingos well should you decide that your lawn needs one of these or you just want to start reenacting random scenes from movies well as I say the gun is available for sale at the Rock Island auction company's sale in September of 2018 anyway this is the first time I've done I think a toad gun so that made an interesting change let's see what comes up next and I'll see you then ok now it's been unscrewed simply lift just a little bit free it up honey can pull this down okay now it's being freed up you can pull it down don't forget to loosen these little locks at the bottom here now they are relegated to simply being lawn armaments armaments

Channel: The_Chieftain

Views: 94,606

Rating: 4.9708915 out of 5

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Id: M3OzxvIvdzM

Length: 18min 36sec (1116 seconds)

Published: Tue Aug 28 2018