Hi guys, thanks for tuning in to another video on ForgottenWeapons.com.
I'm Ian McCollum, and I am here today in
the middle of the Mississippi River at
the Rock Island Arsenal Museum.
Rock Island Arsenal is still 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 two AAI prototype Project SPIW rifles.
We have a 1966 pattern one, and the 1967 pattern.
Now these rifles are both chambered for the [XM-645] single flechette cartridge.
Where they were firing a 10 grain fin-stabilised flechette, obviously.
It had a muzzle velocity of 4,585 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 ... safe, semi-auto,
a mechanically controlled 3 round burst,
or fully automatic as long as you hold the trigger down.
... This one, the 1966 pattern, was developed
for the second generation of Project SPIW rifle trials.
Now this project originated in 1962,
with contracts given out to Springfield Armoury, H&R, Winchester and AAI
to develop rifles for this brand-new generation of US military weapon.
The idea being to be able to fire multiple projectiles
in place of ... one well-aimed single projectile.
That was basically the idea, improve hit probability through volume of fire.
And the first-generation guns didn't really work so well.
The contracts were put out in '62, and the first-generation trials were done in 1964.
And after that Winchester and H&R both dropped out.
Springfield Armoury 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 AAI.
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 imminently be the next US military rifle.
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,
... 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 a traditional rifle because you're firing in bursts.
So ... 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 ... like really bad,
like, they see projectiles hitting the ground 100 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.
... 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 the problem lay in the ammunition assembly.
... They had to do it very, very carefully and precisely in order to make everything work.
You had a sabot on the front of the flechette that had to separate just right.
... The ... sabot 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 sabot 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,
and they had doubling when set to semi-auto.
A lot of these are problems that are the result of under-development.
... They just didn't have long enough. ...
The design process for a gun like this is always a slow one.
You go through and you find a problem, and you resolve that problem.
Then you find the next problem, and 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 acceptable.
Especially when you have a gun that is as unusual in concept as these things.
Did I mention they are primer activated? Because these are actually primer activated guns.
I'll show you that because we're actually going to take this one apart.
Now, after ... the second generation trials the only company left was AAI,
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 ... XM16E1 is chosen, it is clearly better than any of these
catastrophic failures from the SPIW trials, much to many people's dismay.
But AAI 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 are some other changes to it.
And at this point they were finally able to get away from some of
the initial requirements of the SPIW 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 3 round magazine-fed grenade launcher.
And so that added this whole extra level of complexity to the designs,
and also of weight and bulk and just obnoxiousness to the guns themselves.
And this 1966 pattern gun, ... 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 bayonet.
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 ... all that junk and start simplifying the 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 they are primer activated?
Alright, we will start with a look at the 1966 pattern.
The selector switch is here on the side.
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 the front of the trigger guard.
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.
You see we have the elevation lever instead of dial on this side.
The magazine that these used was a plastic 60 round drum magazine.
Nicely labelled on the back there.
You've got little witness holes so you can see how many rounds are in it.
The original SPIW program requirements specified 60 rounds of point target ammunition.
This has a couple of little guide ribs on the back,
and there are a matching set of slots right there, this just slides in.
And we have a lever magazine release.
This whole rifle is extremely lightweight [6.3 pounds with bipod].
I will have to research the actual weight and put it up on the screen as a text overlay,
but ... they almost feel like toy guns.
They are hollow ... plastic furniture, the operating mechanism is very simple,
... it's got a fixed barrel, it has no gas system in it.
Did I mention it's primer activated? 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 ... 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 very muzzle there is what looks like really deep rifling.
And that's actually basically a spinning cutter.
... The bore on this is smooth, it doesn't have rifling because it's a fin-stabilised projectile.
But you have to take the sabot off.
And so this sort of pseudo-rifling right at the muzzle
starts the sabot spinning, and flings it safely off of the flechette.
The only markings on this are on this data plate. It is serial number E-16, ... Aircraft Armaments Inc.
Now moving to the second rifle, the later one, you'll see a later serial number, number E-22.
Similar data plate there.
I realise I never actually put the magazine in the other one.
So that's what it looks like actually in place.
Just pull it right out.
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, AAI was able to dispense with
that whole goofy six function muzzle device on the old guns.
And they were able to go to just a basic muzzle brake.
One of the issues with this is, in order to accelerate the flechette slowly enough
that the sabot stayed on it reliably, they had to use a very slow-burning powder.
And that meant that they ... still had very high pressure at
the muzzle 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 ... this thing measured 162 decibels at the muzzle,
which is 10 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 cookoffs.
So the '66 trials guns had basically not been able to fire reliably enough
to get the gun hot enough to demonstrate the cookoff issues, and by '67 they did.
So they had to institute a couple of other [fixes] to try and ameliorate that.
Most notably, they put a big ol' 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 going to do is ... push this lever forward, and then this rear cap
lifts out of the gun. 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 gun.
It's basically like a tappet.
The primer, when you fire, is going to back out of the [case] 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 carbine's 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 ... 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 buffer spring at the very back.
So this is going to be the last thing that the operating bits 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 ... 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 [M60], like that.
So ... it kind of acts like an open-bolt gun in that it has sort of a fixed firing pin
on the face of that primer-activated piston.
So after this, the program starts to kind of wind down and it turns into just AAI.
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 ... may not even have died yet.
This would go on to be the basis for the Advanced Combat Rifle program in the early 1990s.
It was these concepts that would eventually lead to guns like the HK G11, the Steyr ACR.
And what's funny is even by that point,
some of the people were doing 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. ...
A duplex cartridge might still be something to actually take seriously,
where these flechette firing rifles, and 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
... 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.