PDW Cartridges

[Suputin]

The thread on PDW's got me thinking about the cartridges used in PDW's.

In some cases we just use the same round as is used in the rifle version but lots of the time this is not very efficient due to velocity loss from very short barrels. There are some more PDW friendly cases like 300 Whisper that are not so sensitive to barrel length and then there are the (typically small caliber) rounds specifically designed for PDW use like the FN 5.7 and the HK PDW round.

Thoughts? What round would you like to run in a PDW if you had the choice?

 

[Savage]

10 mm would be ideal good bullet wieght and aceptable performance and good controlabilty

 

[Doc M]

For the AR platform, something in 6mm or 6.8mm may be great - especially with a Whisper-style case for OAL concerns.

An AR redesigned around 5.7x28 would be an interesting mix of existing tech on different platforms, but at that point why not just use a proper PDW from FN to begin with.

Handgun cartridges are great, but lack the body armor penetration and vehicle penetration one wants in a proper PDW - and if using a handgun cartridge, why not just use it in your handgun?

I think a fast 6.8 is a great answer to this kind of problem.

-M

 

[heckler]

Bushmaster 450, maybe .38 super??

 

[Juster]

A military cartridge should have a useful civilian function, some kind of light varminter perhaps.

 

[NavyCuda]

If I could build my own PDW, it would be based on 8mm Kurz.

 

[rivetc78]

Cartridge that matches your secondary.

.45 ACP

 

[KevinB]

Pick a cartridge that gives you your required performance.

I would NEVER recommend using a handgun round in a long gun. Want a handgun, carry one, put why in the earth would you limit your long gun to a unnecessarily anemic round?

I would never use 6.8 in a M16FOW -- just running the bolt thru ANSYS will show you the relief on the bolt rim does not allow sufficient strength -- 6.8 also offers a lot more recoil in small gun than really desired.
Keep in mind 6.8 was designed for a 12.5-16.5" bbl as a compromised cartridge that allowed use of the M16FOW architecture, key word compromise.



5.7x28 (FN) and 4.6x30 (Hk) where designed for a rather usless NATO cross hangun/PDW concept.
Basically you take a long gun, and dumb it down to be cross compatible.

Our (KAC) PDW was designed around an ammuntion that was purpose built for a PDW, a 0-300m requirement (PDW folks may have to shoot it out with AK weilding foes), and to function effectively in a short barreled weapon.

 

[krausb]

A military cartridge should have a useful civilian function, some kind of light varminter perhaps.

you mean something like .223, perhaps?

 

[krausb]

...

Our (KAC) PDW was designed around an ammuntion that was purpose built for a PDW, a 0-300m requirement (PDW folks may have to shoot it out with AK weilding foes), and to function effectively in a short barreled weapon.

Kevin, do you see this cartridge ever going mainstream? Or is it something that KAC plans to keep as more of a proprietary cartridge?

 

[KevinB]

I really dont know -- I have been recommending we take it to SAAMI for over two years.

 

[Ix]

I really dont know -- I have been recommending we take it to SAAMI for over two years.

what caliber is that pretty KAC thing in again?

 

[enefgee]

If a person was able to purchase a 635 upper, would they have to import the ammo from Hornady - or would they be able to bring in just the brass, or..........

 

[krausb]

what caliber is that pretty KAC thing in again?

6 x 35mm

 

[krausb]

I really dont know -- I have been recommending we take it to SAAMI for over two years.

Ah, I see. So is it safe to say that without SAAMI approval, no ammo manufacturer would put this ammo on the market?

 

[winnipegger]

As me and Suputin mentioned in a different thread, I've always wanted a gun in 9x39. It has quite impressive close range potential. (especially in the penetration department) and is adequate i would specualate to 300m. That said compared to 6x35 it is a very bulky and heavy round.

 

[KevinB]

9x39 will not pen soft armor as well as a thinner round.

And it may whistle poorly thru the air in a subsonic.

 

[KevinB]

Ah, I see. So is it safe to say that without SAAMI approval, no ammo manufacturer would put this ammo on the market?

Hornady makes it for us, One Shot could then buy it from us.
However it may end up being prohibitively expensive.

 

[winnipegger]

9x39 will not pen soft armor as well as a thinner round.

And it may whistle poorly thru the air in a subsonic.

I was just thinking more of people and cars and walls. I have no idea about its armour pen caparabilites, I'll take your word on it.

what does whistle poorly thro the air mean? like it is not aerodynamic?

 

[KevinB]

Just had a brain fart on the 9mm subsonic, never mind - ignore that.
I was thinking about the .50 Beowolf subsonic.