AT15 7.5" PDW Carbines

alberta tactical rifle

alberta tactical rifle

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These itty bitty sub-carbines are a bit of a specialist item. We don't build many of them but they are very cool.


The very first 5.56mm PDW carbine we ever put together. It has a 7.5" heavy profile match grade stainless steel barrel. The oversized round forend and SPEX brake make it resemble the ubiquitous MP5SD. Magpul furniture and a C-More sight complete the look.

SPEXBrake1.JPG




The Operator: A more sophistocated PDW. This one wears a Noveski rail and QD vertical grip over top of the 7.5" heavy stainless barrel. The ACE Socom stock, Ergo Grip and one-off custom Cerakote give this sub-carbine a unique look. Belonging to one of our employees it bears one of the original SPEX R&D brakes.

AROperator.jpg




Gen II Operator: 7.5" stainless heavy barrel, Troy rail, ACE Socom long stock, SPEX brake.

AROperator2.JPG



Gen IIa Operator: 7.5" stainless heavy barrel, JP Ent VTac free float forend with top rail, Socom short stock, SPEX brake. This rifle is available for purchase for $2970 ($2720 w/o sights)

AR7inch3.JPG



Oct 2010 Update - got a new one for you guys.

ARPistol4.JPG


We have a small number of 7.5" heavy stainless barrels for sale. $325 each

ARPistolBarrel.JPG
 
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I've built two of these 7.5" shorties.
They look UberCool,
but they ARE LOUD, and the velocities with these short barrel is quite a bit less.[ about 100 fps less ]
AND, more significantly, the spread in velocities is also quite a bit larger.
In 5.56, with these short barrels, a lot of powder gets burned outside the barrel.

My first 7.5" was old technology, with a pig tail gas tube.
It had a F/A bolt carrier, and a rifle length butt with rifle buffer & spring.
It worked reliably.

The second one had a regular pistol length straight gas tube,
and also had a F/A bolt carrier, and a rifle length butt with rifle buffer & spring.
It was also reliable.
However,
given the noise, flame, and power drop involved in these ultra short 5.56 builds, for my next ultra short AR, I am seriously considering a 9mm AR build using one of the LW modifed lowers that take Glock magazines.
Or better yet, a .357 SIG build ...
but that would get ...
COMPLICATED, and quite expensive??

Right now I am playing with a FAB/KPOS carbine conversion kit on my G35, which already has 9mm and a .357 SIG adaptor barrels.
Simple and inexpensive.

If the ergonomics of this Glock ?Carbine? can come close to matching a shorty 9mm AR build, why then I may save myself some money.

And while those 7.5" ARs admittedly do look TactiCool!
my 10.5" LMT AR looks almost as cool, but is significanlty quieter.
[;{)
LAZ 1
 
We also tried a pigtail gas tube at first but ended up going with a straight pistol length gas tube and the rifle works 100%

With a conventional muzzle brake or flash hider, these things are indeed abusive. Hence the reason both are wearing SPEX brakes, which throw the sound and blast downrange, away from the shooter. The SPEX is very good at killing flash as well. This makes these little rifles a lot more fun to shoot.

Velocity and thus ballistics reduction is a MOOT point unless one is planning on shooting people with this thing, which this being Canada we assume nobody is.

We are working on something even smaller and more compact so watch this space. :)
 
Something Smaller and even more compact?

How about an uber-shorty piston driven AR with a side folder?

And just so that short barrel won't break our ear drums,
make it IN .300 WHISPER or 7.62X39 or 9mm or .357 SIG????

Yep, here in Canucklehead Land,
terminal ballistics on these range use only,
long range paper punches,
is pretty well a MOOT ISSUE.

But when you get that short a barrel,
maybe a fatter/heavier bullet is more appropriate than 5.56 [ so these fatter/heavier paper punches can push through Thicker paper ] .
ALSO,

In 5.56, with these short barrels, a lot of powder gets burned outside the barrel,
and the spread in velocities is also quite a bit larger.

Theoretically,
any increase in the spread of velocities may be associated with a decrease in accuracy.
That point is NOT moot!

Any more contributors to the discussion on the merits of
LOUD and slender,
VS less loud, more Heavy,
in AR uber-shorties???

I've never personally played around with a 9MM AR,
so I don't yet know any details, but when you get this short in an AR 15 type fire arm,
why not use a pistol cartridge??

Is the 7.5" AR in 5.56 a 300 yd fire arm?
Is a 9mm AR only a 200 yd fire arm?
Is the extra increase in range worth the much louder muzzle blast and all that powder wasted out side the barrel?

Enquiring minds would like to know,
thanks
LAZ 1
 
Piston drive in a pistol length carbine could be problematic. I don't know of anyone producing a piston drive that short that we can get hold of.

However a side folder is a separate issue. That requires a shortened bolt carrier and a redesigned recoil system. Both of which are achievable.

We are actually contemplating other calibers like 300 Whisper and 6.5 Grendel. We have reamers and the barrels have been ordered and should be here soon.

The problem with 7.62x39 is it doesn't feed through AR mags so well and apparently it is very hard on bolt life. The Whisper is a better solution.
 
please, Please, PLEASE get some .300 Whisper barrels in.
I would buy another .300 Whisper barrel in a second,
as long as it had a twist that was suitable for the HEAVIES.
However,
getting the .300 W brass up here in volume might still be a bit of a hassle.

I brought in two SS 16" barrels, [ which came with pistol length gas tubes ] in .300 Whisper/aka .300 Fireball/aka .221/.30/ aka .30 Sportsman. I put one barrel in to a complete upper, oredered up 1000 rds of once fired/reformed .223/.300 W brass, and a set of .300W dies.

Unfortunately, I had to sell off my .300 Whispers.

I still keep a few .300 Whisper cases loaded with a 230 Gr bullet,
just to remind me of what I missed out on, and to show people at gun shows.

In New Zealand, where snufflers are legal, the .300W with heavy bullets has reportedly been used successfully on their Elk - up to 200 yds.

Gotta like that .300W cartridge ...
perhaps what the AR 15 should have been created with instead of the .223??
Or maybe not?
 
please, Please, PLEASE get some .300 Whisper barrels in.
I would buy another .300 Whisper barrel in a second,
as long as it had a twist that was suitable for the HEAVIES.
Click to expand...

There is really no need to use super heavy bullets for subsonic operation. Even medium weight subsonics have huge penetration so any extra energy is just wasted when the bullet passes through the target. However I believe 1:8 is kind of a standard twist rate for 300 Whisper.

However, getting the .300 W brass up here in volume might still be a bit of a hassle.
Click to expand...

Remington is making new 221 Fireball brass and Wholesale Sports is stocking it. Otherwise 300 Whisper isn't too difficult to make from cut down 223 Rem brass.

I still keep a few .300 Whisper cases loaded with a 230 Gr bullet, just to remind me of what I missed out on, and to show people at gun shows.
Click to expand...

I once got to shoot a suppressed 510 Whisper with API bullets. Tons of fun but a wee bit too expensive and difficult to live with for my liking. I am a big fan of the 300 Whisper though.

Gotta like that .300W cartridge ...
perhaps what the AR 15 should have been created with instead of the .223??
Or maybe not?
Click to expand...

FWIW the 300 Whisper was specifically designed to go through the AR platform with minimal fuss.
 
PWS diablo is a 7" piston upper, works flawlessly.



alberta tactical rifle said:
Piston drive in a pistol length carbine could be problematic. I don't know of anyone producing a piston drive that short that we can get hold of.

However a side folder is a separate issue. That requires a shortened bolt carrier and a redesigned recoil system. Both of which are achievable.

We are actually contemplating other calibers like 300 Whisper and 6.5 Grendel. We have reamers and the barrels have been ordered and should be here soon.

The problem with 7.62x39 is it doesn't feed through AR mags so well and apparently it is very hard on bolt life. The Whisper is a better solution.
Click to expand...
 
Quote:
Originally Posted by alberta tactical rifle
Velocity and thus ballistics reduction is a MOOT point unless one is planning on shooting COYOTES AND DEER with this thing, which this being Canada we assume nobody is.

I fixed that paragraph for ya.
Click to expand...

REALLY. You planning to take a 7.5" restricted firearm out to shoot coyotes and deer with?
 
When it comes to these shrunken shooting platforms [ ?PDWs? CQB Optimised Carbines? ] shortening the barrel on a mouse gun in poodle shooter caliber, doesn't seem anywhere near as "practical" to me as lengthening the barrel of a larger bored pistol cartridge.

If I was building myself a dedicated, short barreled, range use only, hi speed, lo drag, go faster gun, for the short range stages in a three gun match, a pistol caliber AR, with 10 RD Glock mags, makes a LOT of sense. In either 9mm or .40, there are some mature, well developed top ends out there to bolt on to the Glock optimised lower. But neither 9mm nor .40 is gonna be much good past 100 - 150 yds. If I was building myself an actual Pistol caliber PDW, this is where the .357 SIG really gets interesting for me.

And if i was building an honest to gawd "Thumper", then a pistol /carbine conversion, or an AR set up in .45 SUPER, would be fun to play with.

If cost is the primary concern, so far my initial impressions tell me that I like the FAB/KPOS Glock carbine conversion kit
The Glock pistol into carbine conversion kit costs only $ 400 more than what I already have invested in my G35 Glock, with mags and .357 SIG Caliber conversion barrel and ammo, and red dot optics already in the kit locker.

If ergonomics and Maximum TactiCOOL Points are more important concerns,
then a Lone Wolf or OLY AR 15 lower, set up to use 10 rd Glock mags, makes some sense. Most 9mm uppers WILL reportedly work with the .40 S&W Glock mags, with no grinding of the bolts. Reaming a 9mm barrel to take .357 SIG, and getting a .40 S&W bolt would complete the build.
IN THEORY any how, it could be just that simple.
BUT FRIGGIN EXPENSIVE!!!!

And for optimum Tacticool points,
The other caliber that would make sense to me is .45 ACP, and also set up to shoot .45 SUPER. BTDT with .45 Super in a couple of Colt Govt builds, with 6" RAMPED barrels, which I built for Bowling pin matches, and for any surprise close range encounters with Grizzlies and BEM Aliens.

Now THERE is an interesting caliber.
.45 Super, as chronoed by me in my test loads, gave muzzle velocities of:
230 Gr FP FMJ bullets at 1250 FPS.
180 Gr HARD CAST OMA lead wad cutters at 1400 PS .

Yep,
imagine a .45 SUPER Glock carbine,
or an AR 15 hybrid,
that can use .45 ACP for practice???
Now wouldn't THAT be sumthin'??

PS: YES I have heard of .458 SOCOMfortable, .50 BIG BAG WULF, and a few of the other proprietary AR 15 "THUMPER" cartridges, but they don't use cheap .45 ACP ammo for practice.

PPS:
http://www.rockriverarms.com/index.cfm?fuseaction=category.display&category_id=441

RRA has their new piston driven, zero length buffer tube, PPS pistol available in .223,
and their other AR pistols in .223 AND .40 S&W and in 9 mm ...
so I'd bet we will soon be seeing a RRA PPS in .40 S&W and in 9 mm AND maybe ev en in .357 SIG???
Gotta like that PPS non-reciprocating ambi cocking handle.

And when they hit the market, why not import some of these to Canuckistan??
or better yet,
JUST THE PPS pistol caliber UPPERS, so we could bolt them on to LW Glock mag lowers??
[;{)
LAZ 1
 
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