PDW/SBR Preference Rankings

[Precision]

Just by personal preference, how would you rank these "mini-mowers" from 1-4?

LWRC PSD: http://www.lwrci.com/p-111-psd.aspx
POF-USA PDW: http://www.pof-usa.com/pdw/pdw.htm
KAC PDW: http://knightarmco.com/pdw.html
Robarm XCR-L Micro: http://robarm.com/resources/products/xcrlmicro/index.aspx

P.S. I wanted to use the term "baby-boomers" instead of "mini-mowers," but decided that its connotation could easily be heavily misunderstood

 

[Maverick223]

...and the P-90/PS-90 didn't make the list?

 

[unwise11]

I handled one of those LWRC's and I have to say it's impressive, I'd vote for it.

 

[Ian]

I'm pretty fond of my shorty AK...

I'd be a bit surprised if there's more than one or two folks here who actually have enough experience with all four of those to have a legitimate preference.

 

[Sam Cade]

The KAC-PDW does not exist beyond prototype.

I've not even seen the shorty XCR or LWRC.

I've ran a couple magazines through a 11.5" POF upper. Very effective muzzle-break. Unbelievability loud, left unburnt powder all over my forearms and face.

 

[Bartholomew Roberts]

Well, except for the KAC, all of them are firing intermediate rifle cartridges designed for longer barrels out of 9" or less barrels. So you've reduced the effectiveness of the cartridge noticeably and added a lot of blast and flash.

I would think the KAC has the advantage because it is originally designed as a PDW instead of being an existing rifle cut down to PDW size. However, not having shot any of those, or having the first clue of which was better, that's just a guess on my part.

If you made them all available to me for sale, I'd probably still opt for one of the 5.56mm PDWs on the basis that whatever advantages the KAC PDW might have are probably not worth the percentage of my discretionary income it would consume.

 

[jerkface11]

magpul pdr http://en.wikipedia.org/wiki/Magpul_PDR

 

[Zerodefect]

Ps90.

Even with the 16" barrel. As long as it has a Tros USA lowmount and an Aimpoint anyway.

 

[SentinelStrategic]

The KAC-PDW is a .mil/.gov only weapon. As of yet, I am unaware of any that have been issued yet.
Still, the KAC-PDW is a proper PDW/SMG platform. The 6x35 platform sits in the competing category with the 4.6mmHK and 5.7mmFN, but it has the most energy and largest projectile.

If I was picking one to buy right now, it'd have to be the POF PDW.

Well, except for the KAC, all of them are firing intermediate rifle cartridges designed for longer barrels out of 9" or less barrels. So you've reduced the effectiveness of the cartridge noticeably and added a lot of blast and flash.

There is a significant amount of flash and muzzle concussion to be sure. However, the effectiveness of the cartridge is really only heavily diminished at longer ranges. At closer ranges, PDW barrels still are able to produce sufficient velocity on bullets 55gr and lighter to be effective, provided that they have a 1:7 twist rate. What needs to be taken into account is the type of ammunition being used. 55gr is the heaviest you want to use according to Hornady's specs. The issue is actually interesting. I have PSD/PDW custom build with a Noveske Diplomat 7.5" barrel. Depending upon ammo, I can get between 2300 and 2700fps muzzle velocity for rounds ranging from 55gr down to 40gr Hornady TAP Urban. You will have ~600fps loss from a 16" barrel down to 7". I've found that you tend to get deeper penetration with those rapid expansion urban rounds (Hornady TAP Urban/TAP-FPD, Federal TRU) due to less immediate explosive expansion, which is interesting. Not as good as a standard 16" carbine, or even as much as say, an 11.5" SBR. Still, it's lethal at the ranges that a PDW would be employed.