PDW Cartridges

In some cases, you're seeing even modestly equipped police services switch from subguns to PDW's. I know that the Halifax Police Department (HPD) use to have MP5's and now they're using P90's as a replacement. Some officers are carrying them in their patrol vehicles. I've handled the P90 but I've never had the opportunity to shoot one.

The officer that showed me the weapon indicated that HPD wasn't exactly thrilled with the cost of ammunition which made training a very costly endeavour.
 
Sub gun still have their use, and that's why JTF are still carrying MP5K PDW, and the main advantage is the size. Rifle round work with speed, especially 5.56/.223, the faster it goes the better, that's why numerous study show that very short barreled rifled M4 are nothing more than .22 magnum. Pistol round on the other hand work more with weight and size of the bullet, so can have a very small weapon with a small barrel, a lot less recoil for follow up shot (easier for head or pelvis shot) and in short range (under 50) with good JHP bullet you might even have the same or even better terminal ballistic than a 5.56 shot from a short barrel (10inch) .
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Subguns are a pretty mature technology where PDW's are still developing. In time the PDW will fully supplant the SMG except for very specialized requirements.

PDW sized 556 weapons are as you note, not all that effective terminally. However an AR or M4 in 300 Whisper doesn't suffer from velocity loss in a short barrel and so is much more effective than either its 556 parent or any subgun.

The KAC 6x35 round is an excellent choice for a PDW because it offers low flash and recoil as well as improved terminal ballistics from its bigger bullet. The downside to the 6x35 is that it does not work through an AR platform nor will it feed from AR mags. It requires a specialized gun and magazines that are not available at this time.
 
vagrant said:
Sub gun still have their use, and that's why JTF are still carrying MP5K PDW, and the main advantage is the size. Rifle round work with speed, especially 5.56/.223, the faster it goes the better, that's why numerous study show that very short barreled rifled M4 are nothing more than .22 magnum. Pistol round on the other hand work more with weight and size of the bullet, so can have a very small weapon with a small barrel, a lot less recoil for follow up shot (easier for head or pelvis shot) and in short range (under 50) with good JHP bullet you might even have the same or even better terminal ballistic than a 5.56 shot from a short barrel (10inch) .

But its still a pistol round and that's why the knight PDW is very interesting, the round is clearly a medium between both. Make me think a bit like the AK74SU, that also as a nice little under appreciated round
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Blah blah blah.
Anyone who really knows how things are done and what gets carried on the hill have signed nondisclosure agreements.
 
One reason a lot of Subguns still exist in inventories is budget.

Several Big Name entities have adopted pistol cal PDW's and transitioned away due to mission failure on the platform.
There is a rather infamous document circulating from DocGKR to several entities explaining the best way to ensure mission failure would to be issue a P90...


The best way to look at it is what is the mission?
What is your engagement profile?

That will dictate what weapon platform, and in some cases you need to make tradeoffs in performance to gain the ability to discretely carry a weapon.



Despite our (KAC) commentary previously to the contrary - I recently fired several hundred rounds of 6x35 thru a SR-635 using PMAG's. This was done almost entirely on auto in 30 rd mag dumps. At this point I would not say it is definitive, but I beleive that we are going to shelf our work with Magpul on a specific mag, and just recommend the PMAG, note USGI mags will not work well, regardless of followers.
 
Gunnerlove said:
Blah blah blah.
Anyone who really knows how things are done and what gets carried on the hill have signed nondisclosure agreements.
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i know they use C8, i know what kind of flashbang they use, what kind of breaching round and other, and i don't need to be in their pants for that. They have way more important information to hide than the fact that they use MP5K.

its the same as colt Canada won't tell you the SAS use the Colt C8 SFW, everybody know, but they won't tell you.
 
KevinB said:
One reason a lot of Subguns still exist in inventories is budget.

Several Big Name entities have adopted pistol cal PDW's and transitioned away due to mission failure on the platform.
There is a rather infamous document circulating from DocGKR to several entities explaining the best way to ensure mission failure would to be issue a P90...


The best way to look at it is what is the mission?
What is your engagement profile?

That will dictate what weapon platform, and in some cases you need to make tradeoffs in performance to gain the ability to discretely carry a weapon.


Despite our (KAC) commentary previously to the contrary - I recently fired several hundred rounds of 6x35 thru a SR-635 using PMAG's. This was done almost entirely on auto in 30 rd mag dumps. At this point I would not say it is definitive, but I beleive that we are going to shelf our work with Magpul on a specific mag, and just recommend the PMAG, note USGI mags will not work well, regardless of followers.
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Is this document available to the general public? If so, I would love to see it!

I know JTF2 uses (or used too) the P90. Is this not the case anymore? You figure if anyone would be on top of the whole PDW game, it would be a group like JTF2.

*edit - here is a thread by DocGKR on m4carbine.net, some of you may find this interesting: http://www.m4carbine.net/showthread.php?t=19913

Some papers recommended by DocGKR:
Several papers have described the incredibly poor terminal performance of the 5.7 x 28 mm projectiles fired by the FN P90:

--Dahlstrom D, Powley K, and Gordon C: “Wound Profile of the FN Cartridge (SS 190) Fired from the FN P90 Submachine Gun". Wound Ballistic Review. 4(3):21-26; Spring 2000.
--Fackler M: "Errors & Omissions", Wound Ballistic Review. 1(1):46; Winter 1991.
--Fackler M: "More on the Bizarre Fabrique National P-90", Wound Ballistic Review. 3(1):44-45; 1997.
--FBI Academy Firearms Training Unit. FBI Handgun Ammunition Tests 1989-1995. Quantico, U.S. Department of Justice--Federal Bureau of Investigation.
--Hayes C: “Personal Defense Weapons—Answer in Search of a Question”, Wound Ballistic Review. 5(1):30-36; Spring 2001.
--Roberts G : “Preliminary Evaluation of the Terminal Performance of the 5.7 x 28 mm 23 Grain FMJ Bullet Fired by the New FN P-90 , Using 10% Ordnance Gelatin as a Tissue Simulant”, AFTE Journal. 30(2):326-329, Spring 1998.
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Despite our (KAC) commentary previously to the contrary - I recently fired several hundred rounds of 6x35 thru a SR-635 using PMAG's. This was done almost entirely on auto in 30 rd mag dumps. At this point I would not say it is definitive, but I beleive that we are going to shelf our work with Magpul on a specific mag, and just recommend the PMAG, note USGI mags will not work well, regardless of followers.
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Not sure how you managed that. I have been having issues with our 6x38 feeding properly and it is longer than the 6x35.
 
beltfed said:
I'd take .22 LR over 5.7x28....
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I hear that a lot. However the military 5.7 round is armor piercing shoots 2350 FPS for the SS190 AP round out of a P90. I'm also not convinced that the current ballistic jelly tests realistically show the shock trauma inflicted on sensitive organs by a smaller higher velocity projectile dissipating it's energy around those organs rather than simply a larger or longer wound cavity. The shock may cause those organs to shut down.

In testing in 1999 by the Royal Canadian Mounted Police (RCMP), the SS190 fired from the P90 at a distance of 25 m (27 yd) exhibited an average penetration depth of 25 cm (9.85 in) in ballistic gelatin after passing through a Level II kevlar vest.[

Yes it would also make a decent little varmint round.

Oh and it has the recoil of a 22LR. IE almost none and is designed to fit into a 50 round magazine. Although Canadian laws screw us on that one. They eject out the bottom with the FN mag.

Is there better. For certain situations absolutely. But I still think the 5.7 doesn't get it's fair share of respect.

FN PS90

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AR-57

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Epoxy7 said:
I hear that a lot. However the military 5.7 round is armor piercing shoots 2350 FPS for the SS190 AP round out of a P90. I'm also not convinced that the current ballistic jelly tests realistically show the shock trauma inflicted on sensitive organs by a smaller higher velocity projectile dissipating it's energy around those organs rather than simply a larger or longer wound cavity. The shock may cause those organs to shut down.

In testing in 1999 by the Royal Canadian Mounted Police (RCMP), the SS190 fired from the P90 at a distance of 25 m (27 yd) exhibited an average penetration depth of 25 cm (9.85 in) in ballistic gelatin after passing through a Level II kevlar vest.[

Yes it would also make a decent little varmint round.

Oh and it has the recoil of a 22LR. IE almost none and is designed to fit into a 50 round magazine. Although Canadian laws screw us on that one. They eject out the bottom with the FN mag.

Is there better. For certain situations absolutely. But I still think the 5.7 doesn't get it's fair share of respect.

FN PS90

images


AR-57

images
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I agree. I'm going to do some gel tests with my 10" PS90. I'd like to see for myself how it does and compare it to a 10" AR.
 
Well honestly we are doing more testing. The original test gun our R&D Director and I built shot 750 rds of 6x35 in a PMAG no issues.

We had issues with USGI mags and looking at the geometry figure that a dedicated mag would work better than a PMAG, and are having MAGPUL work on it with our design (they are experts in Polymer mags).

As for the P90 and MP-7, admittedly I work for a competitor, so take what I saw with a grain of salt, but I've seen FTS with multiple rounds from those, and have a ton of friends who have seen and had the same issue on their entities guns.

Like it or not Gel does accurate portray actual bullet results in human tissue.

A P90 user group that dropped it ;) Open Source photo posted previous on AR15.com
USSSSR-16E3CQB.jpg
 
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