AAI 2nd Gen SPIW Flechette Rifles

hi guys thanks for tuning in to another video on Forgotten weapons calm I'm in Collin land I am here today in the middle of the Mississippi River at the Rock Island Arsenal Museum Rock Island Arsenal is still a an active and functional US military base and they have a very cool little small arms museum on base which has a bunch of really interesting prototype rifles that they were generous enough to let me take a look at and bring to you guys specifically today we are taking a look at to a AI prototype projects pew rifles we have a 1966 pattern one and the 1967 pattern now these rifles are both chambered for the X m1 45 single flechette cartridge where they were firing a 10 grain fin-stabilized flechette obviously had a muzzle velocity of 4500 and 85 feet per second so extremely high velocity these guns are set up with 60 round drum magazines and the fire selectors on them allow you well safe semi-auto a mechanically controlled 3 round burst or fully automatic as long as you hold the trigger down and these were developed well this one the 1966 pattern was developed for the second generation of projects pew rifle trials now this project originated in 1962 with contracts given out to Springfield Springfield Armory hnr Winchester and AAI to develop rifles for this grand new generation of US military weapon the idea being to be able to fire multiple projectiles in place of a single of one well-aimed single projectile it was basically the idea improve hit probability through volume of fire and the first-generation guns didn't really work so well the the contracts were put out in 62 and the first generation trials were done in 1964 and after that Winchester and HN are both dropped out Springfield Armory pretty much dropped out as well because right about this time they were being shut down by Robert McNamara so they weren't doing any more developmental work and it all kind of fell down onto a AI now the second generation trials did have both Springfield and aai rifles in it those trials took place in 1966 and at this point there was still a hope the idea had been that this was going to eminently be the next US military rifle you know they were expecting like a type classified rifle by I think 1967 this of course obviously never happened and the problem was in the 1966 trials with this guy they had it was just like a complete explosion in flames of problems with these guns they had a lot of reliability problems they had a lot of accuracy problems you know the idea had been you don't need really nearly as much accuracy as as a traditional rifle because you're firing in bursts so you know you're not going for one minute of angle and you'll never get that really with a flechette fired from a rifle the problem was they were getting really like really bad like they see projectiles hitting the ground a hundred yards in front of the shooter when he's shooting at the 200 yard berm that kind of problem and I think a lot of that stemmed from ammunition while the guns were capable of actually doing remarkably well like 12-inch mean radius groups at 300 yards you know that that's kind of crap by rifle standards but for a fin-stabilised dart that's not bad at all the problem was this ammunition I think I think the problem weigh in the ammunition assembly that they had to do it very very carefully and precisely in order to make everything you work you had a say bow on the front of the flechette that had to separate just right you know if the the Flex a bow was supposed to separate into four pieces if like one of them stuck a little too long that would dramatically affect your accuracy if the Sabo managed to like blow off the front of the flechette that's going to hugely impact your accuracy and as they tried to start increasing volume of production on the cartridges problems like this were the result now in addition to that they had reliability problems with the guns they had a lot of parts failures they had like the fire control groups would not quite work quite right they had doubling when set to semi-auto a lot of these are problems that are are the result of under development you know they just didn't have long enough to the design process for a gun like this there's always a slow one you go through and you find a problem and you resolve that problem then you find the next problem you resolve that and they're usually these small little incremental things and it takes a long time to get a gun from initial concept to actually being militarily you know acceptable especially when you have a gun that is as unusual in concept as these things did i mention their primer activated because these are actually primer activated guns I'll show you that because we're actually gonna take this one apart now after this first trial or after the second generation trials the only company left was a AI because Springfield was effectively gone and they actually got a contract to continue developing the gun and to try and make something work the whole project has pretty much fallen apart at this point the m16 the ex m16a1 is is chosen it is clearly better than any of these catastrophic failures from the spew trials much to many people's dismay but AI would go on to continue working on them and the next thing that they came up with was this guy so it's mostly distinctive from the outside from the muzzle brake but there's some other changes to it and at this point they were finally able to get away from some of the initial requirements of the spew trials that were kind of hampering everything that came before these trials had included originally in the first generation the guns had to also include a three round magazine fed grenade launcher and so that added this whole extra level of complexity to the the designs and also of weight and bulk and just obnoxiousness to the guns themselves and this 1966 pattern gun still the muzzle we'll take a look at this up close in a moment the muzzle is absolutely covered in lugs because it was capable of mounting a grenade launcher and a bipod and a ban at and it had to be according to trials after that second generation trial was over the 1967 pattern gun they were able to get rid of that that junk and and start simplifying a gun and try and make it good at just being a flechette firing high rate of fire rifle so let's take a closer look at these most notably how they actually work did I mention their primer activated all right we will start with a look at the 1966 pattern selector switch is here on the side you know all of these prototypes are a little bit wonky so you have to push that button in and then rotate the selector to whatever position you want and the safety is actually this little flapper in front of the trigger garden so when that's up it's a really pretty obvious safety and you push it down and then you can fire instead of dials these actually have like notched levers for adjusting your windage and your elevation and that's what those are these have aperture rear sights which is kind of nice see we have the elevation lever instead of dial on this side the magazine that these used was a plastic sixty round drum magazine nicely labeled on the back there you've got a little witness hole so you can see how many rounds are in it the original spew program requirements specified 60 rounds of point target ammunition this has a couple of little guide ribs on the back and there are a there's a matching set of slots right there this just slides in and you have a lever magazine release this whole rifle is extremely lightweight I will have to research the actual weight and put it up on the screen as a text overlay but just they almost feel like toy guns they are hollow hollow plastic furniture the operating mechanism is very simple there's it's got a fixed barrel it has no gas system in it did I mention its primer activated well we'll touch on that in a moment but we should take a look at the muzzle here for the 66 pattern this is quite the busy muzzle device so on the bottom we have a pair of lugs while a trio of lugs here that are for the grenade launcher it is removable the lug on the right side of the barrel was there for the bayonet and the lug on the top was for the detachable bipod all of these things required by the original RFP you can just barely see it there but at the at the very muzzle there is what looks like really deep rifling and that's actually basically a spinning cutter to the bore on this is smooth it doesn't have rifling because it's it's a fin-stabilised projectile but you have to take the sabo off and so this sort of pseudo rifling right at the muzzle starts the Sabo spinning and flings it safely off of the flechette the only markings on this are on this data plate is serial number II 16 C aircraft armaments Inc now moving to the second rifle the later one you'll see later serial number number 22 similar data plate there I realized I never actually put the magazine in the other one so that's what it looks like actually in place just pull it right now these magazines obviously contributed problems to the guns reliability because they're drum magazines and drum magazines kind of never work quite right but with the end of the formal military trials AI was able to dispense with that whole goofy you know six function muzzle device on the old guns and they were able to go to just a basic muzzle break one of the issues with this is in order to accelerate the flechette slowly enough that the Sabo stayed on it reliably they had to use a very slow burning powder and that meant that they had a very high they still had very high pressure at the muzzle when the cartridge actually left the barrel when the projectile left the barrel so this led to extraction problems because it was extracting under very high pressure it led to noise problems apparently the this thing measured a hundred and sixty-two decibels at the muzzle which is ten decibels higher than an m16 this was a really loud rifle with their in-house testing aai and I suspect part of this was by being more careful in their ammunition construction they were able to really solve a lot of the reliability problems in 67 that had been exhibited in the 66 trials and that's a good thing it's also a bad thing in that it revealed that they had a serious problem with cook-offs so the 66 trials guns had basically not been able to fire reliably enough to get the gun hot enough to demonstrate the cook-off issues and by 67 they did so they had to institute a couple other issues to try and ameliorate that most notably they put a big old fin radiator on the barrel so this is the 67 gun and here's the trials 62 gun which you can see does not have any sort of radiators just a smooth barrel they would continue developing this rifle with an eye towards fixing some of these problems they would eventually develop an open bolt firing mechanism for the full auto settings which this one doesn't have this is still a closed bolt firing gun now we do need to take it apart so it's actually really quite simple what we're gonna do is push this lever forward push this lever forward and then this rear cap lifts out of the gun and then I can pull this assembly back to here pull out the charging handle and then take all of the internals out like so and because this is a primer activated gun this is pretty much it for operating parts there is no gas system there is no recoil system the barrel is fixed what happens instead is that the cartridge is designed so that the primer actually deliberately backs out of the cartridge when you fire if we take a look at the bolt face you'll see that it has what looks like a really large firing pin in it and the reason is that's both the firing pin and the short stroke piston that operates the it's basically like a tappet the primer when you fire is going to back out of the gun and push this piece push this guy backwards until it's flush with the bolt face right there that is enough force just like an m1 carbines tappet system to move this whole bolt carrier and spring assembly backwards it'll move a little bit under direct pressure and then it has enough residual energy to cycle the whole thing back and eject the cartridge and load a new one the primer actuation is the operating system we also of course have to have a locking system and that is a two lug rotating bolt so when the gun is in battery the bolt lugs as you can see are rotated slightly up this direction and as the piston moves backwards it's going to track in this slot you'll notice it has a lot of dwell time here and that's to try and let some of the pressure of this very slow burning powder in the flechette cartridge let some of that pressure drop but once it moves all the way back to here it's then going to force the bolt to unlock rotate to unlock and then the whole thing can cycle together this attaches to the rest of the carrier guide through this dovetailed connection right there and this guy is just the housing and the mainspring the one last little feature we have is this really heavy upper spring at the very back so this is going to be the last thing that the operating it's impinge on when they're cycling just to dampen the impact so the gun doesn't break now the way the firing mechanism works with this primer activated system is that the sear actually catches the bolt or the firing pin piston component before it's all the way forward so once it's cocked the handle is here and when you pull the trigger it's going to drop forward and fire kind of like an FG 42 or an m16 like that so that's how the thing it kind of acts like an open-bolt done in that it has sort of a fixed firing pin on the face of that primer activated piston so after this program starts to kind of wind down and it turns into just a ai this program would limp along for years trying to get something that was going to work well and they never really did ultimately the idea I don't know the idea may have may not even have died yet this would go on to be the basis for the advanced combat rifle program in the nineteen 1990s it was these concepts that were would eventually lead to guns like the HK ng 11 the Steyr ACR and and what's funny is even by that point some of the people were doing you know single fired high-velocity flechette cartridges and some of them like Colt were still going back to the duplex cartridge idea that at the very beginning even in the 50s on paper was not only like the most effective it was also the lowest risk had a duplex cartridge might still be something to actually take seriously where these flechette firing rifles and then that the caseless high-velocity rifles all of those have some serious fundamental technical hurdles to try and get over I wonder if there isn't still a place for a duplex cartridge today but of course that is a question for another time hopefully you guys enjoyed the video I would like to once again thank the Rock Island Arsenal Museum for letting me take these down off the wall and show them to you guys if you would like to see not just these two but a whole slew of other really equally goofy-looking interesting prototypes in fact from the entire span of US military history I believe there is even a collection of firearms that were surrendered ultimately surrendered from the Little Bighorn still on display here so if you're in the Quad Cities area make sure to make an appointment stop by the museum check their hours first there are kind of limited odd hours but you won't regret taking the time to get on base and take a look at the museum thanks for watching

Channel: Forgotten Weapons

Views: 534,670

Rating: 4.9661922 out of 5

Keywords: history, development, mccollum, forgotten weapons, design, disassembly, kasarda, inrange, inrangetv, aai, spiw, 2nd gen, flechette, special purpose infantry weapon, springfield, 1966, 1967, trials, prototype, experimental, museum, rock island, arsenal, acr, duplex, triplex, second generation, overheat, accuracy, cook-off, us army, m16e1, m14, advanced combat rifle, rifle, burst

Id: qFANjlr4I9Q

Length: 17min 40sec (1060 seconds)

Published: Mon Jun 24 2019