PDWs...and other small arms.

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    I graphed out an assault rifle design following the P90 magazine orientation back in 2005, but ran into trouble with the exact problem stanc pointed out: case taper for longer cartridges. The 5.7x28 does in fact have zero case taper on the wall. The P90 uses a recoiling barrel to deal with pressure, which would not be conducive to accuracy for a modern assault rifle, so I looked into a rotary locking system in a larger bullpup profile with a longitudinal top-fed magazine, with bottom eject.

    Another big constraint with that concept is the magazine width, as mentioned already. It would make a pretty bulky gun, especially if the COAL was increased to escape the limitations of the AR15 magwell. It is an interesting idea though. I toyed with several designs based off that system to include PDW's, DMR's, and grenade-launcher combos that pack a lot of firepower into a very small profile. One of the things I addressed was firing hand functioning of common controls: selector manipulation, bolt catch, mag release, and others I won't mention. The P90 requires two hands to operate when changing mags if you keep your firing hand on the grip.

    If any of you have felt the FN2000, it is horribly bulky...to the point where you can't even get a good sight picture without canting the gun with iron sights. It also has no bolt hold-open device, and sucky mag change characteristics. There is another way of dealing with bullpups that has not been explored yet.

    LRRPF52

    Comment

    • Tony Williams

      #32
      Originally posted by LRRPF52 View Post
      There is another way of dealing with bullpups that has not been explored yet.
      I explored a few alternatives here: http://www.quarry.nildram.co.uk/bullpups.htm

      Comment


      • #33
        Tony,

        You touched on one of the avenues I've been looking at in your discussion, but it still needs to be thoroughly-tested before it can be deemed viable. It's the most practical one, and several designs in buttstock/cheek geometry currently would support it. One of the challenges with the top-mount magazine design I ran into is magazine capacity for assault rifle cartridges, which the 5.7 easily overcomes being so small. It's very difficult to get a 30rd magazine into that P90 style configuration when dealing with a .444" cartridge base.

        LRRPF52

        Comment

        • stanc
          Banned
          • Apr 2011
          • 3430

          #34
          Despite the objections to an SBR -- and an M16 SBR, in particular -- raised earlier in this thread, note that Israeli AFV crews are actually using such a weapon as a PDW:

          In this picture, Captain Dima Levitas, who lost his life in combat during operation "Protective Edge"

          Comment

          • Trooper
            Unwashed
            • Oct 2014
            • 21

            #35
            Originally posted by stanc View Post
            Despite the objections to an SBR -- and an M16 SBR, in particular -- raised earlier in this thread, note that Israeli AFV crews are actually using such a weapon as a PDW:

            https://www.flickr.com/photos/shimsh...n/photostream/
            We had a number of Human Intel teams using 11.5 M4s. Same with Psy Ops and CA.

            Comment

            • stanc
              Banned
              • Apr 2011
              • 3430

              #36
              Vindication!

              15 years ago ARMOR Magazine published my idea for a "true" PDW:


              Now, B&T is marketing a PDW that is virtually identical in concept:





              Comment

              • BjornF16
                Chieftain
                • Jun 2011
                • 1825

                #37
                Nice article...well done! IMO, long overdue in coming to market
                LIFE member: NRA, TSRA, SAF, GOA
                Defend the Constitution and our 2A Rights!

                Comment

                • Lightning8
                  Warrior
                  • Jun 2015
                  • 136

                  #38
                  Just buy the SIG MPX 9mm to go along with the SIG 320 9mm and be done with it.

                  Comment

                  • TOU
                    Bloodstained
                    • Dec 2016
                    • 43

                    #39
                    Originally posted by bwaites View Post
                    Well, the Beo, .458, and .450 are all surely fight stoppers out to 200, but carrying ammo for them is not exactly comfortable. Remember, only 10 rounds to a mag, so even 10 mags only gets you 100 rounds of ammo!

                    BUT...boy do they make people drop what they are doing and come look!

                    I suspect that if you were clearing a room, the first couple shots would make everyone there rethink their options!
                    I had understood that the .50 Beo was task specific in its design. I.E. That it was specifically designed for one reason & one reason only...shoot into & stop engine blocks of party crashes over in Afghanistan & Iraq...in a lightweight AR platform. Not necessarily shoot individuals let alone in close quarters. So I was told...
                    Last edited by TOU; 01-26-2017, 03:47 AM.

                    Comment

                    • Klem
                      Chieftain
                      • Aug 2013
                      • 3507

                      #40
                      Ammunition weight is an important criterion in the PDW debate. It needs to compact and light, including the carried ammunition.

                      The venerable .45ACP firing 230gn projectiles can be eliminated for this reason alone however its impact on flesh relative to supersonic rounds renders it out of the question. Similarly the .50Beo and the 300 Blackout. A 300rd load-out is too heavy relative to 5.56.

                      Comment

                      • BluntForceTrauma
                        Administrator
                        • Feb 2011
                        • 3897

                        #41
                        Originally posted by TOU View Post
                        Not necessarily shoot individuals let alone in close quarters. So I was told...
                        Although it DID fold in half an enemy combatant in AFG when the round took a chunk out of his spine.
                        :: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets

                        :: I Drank the Water :: Revelation 21:6 ::

                        Comment

                        • TOU
                          Bloodstained
                          • Dec 2016
                          • 43

                          #42
                          Originally posted by BluntForceTrauma View Post
                          Although it DID fold in half an enemy combatant in AFG when the round took a chunk out of his spine.
                          Don't get me wrong...I imagine it is fine for "folding" enemy combatants & would think it was very effective. I was just told that it was not its original intended purpose or use when it was initially designed. That it was very task specific in its original design & intent...that is not you say it wouldn't have other uses & applications. Also that other calibers would be just fine for enemy combatants...maybe even preferred especially when it came to distance, weight, recoil & magazine capacity. But hey...I'm only an ACQ and whole heartily defer to those that have "been there, done that."

                          Comment

                          • n9nwo
                            Bloodstained
                            • Dec 2016
                            • 93

                            #43
                            Originally posted by stanc View Post
                            Some individuals -- including yours truly -- argue that the military should adopt a "true" PDW, like the B&T MP9 ( http://www.65grendel.com/forum/showt...ull=1#post3894 ).

                            However, I recall reading in Infantry magazine back around 2004-2006, that the US Army had opted for a 10.5" barrel version of the M4A1 carbine for the personal defense requirement. (See attached photo of such a weapon being carried by a senior non-com in late 2007.)

                            Since Variable has been shooting a similar short-barrel carbine in 6.5 Grendel for some time, it would seem like a suitable option for a military PDW.
                            Look at the Tavor, especially the new X95 (vs. the SAR). Very easy to swap barrels which is done in the .300 BLK version. Everyone is doing 300 BLK due to being based on the same case as the .223 REM

                            For a 6.5 Grendel it would take having the rifle to have a AK (7.65x39) bolt. My guess is that is coming.

                            Comment

                            • Texas
                              Chieftain
                              • Jun 2016
                              • 1230

                              #44

                              Comment

                              • LRRPF52
                                Super Moderator
                                • Sep 2014
                                • 8569

                                #45
                                A PDW needs to be so compact, it can be worn on the belt and forgotten about, without any snag hazards, while still addressing terminal performance that most pistol cartridges fail to do well at all. When looking at terminal performance studies of handgun cartridges across thousands of samples, you see a very high survivability rate with pistols, and not so with rifles. You're basically looking at around a 25% kill rate with handguns, and at least 65% with rifles.

                                Any straight-walled pistol cartridge simply doesn't have the speed/projectile weight to do the job. Any legacy 20th Century pistol cartridge should be excluded on that basis alone, in addition to the fact that they all have terrible effective ranges due to low mv and poor projectile shaping.

                                When you look at things like the 7.62x25 and other small, bottle-necked cartridges, things start to shift towards rifle performance. 9x25 Dillon is another example of a pistol cartridge that can spit a decent weight projectile at 2000fps or more.

                                Support MOS soldiers need a little box-shaped weapon that is unobtrusive, goes on their belt, and is out of the way throughout the day, but there if something goes horribly wrong (green on blue, Major Hassan type events, vehicle disabled outside the wire, etc.). We're talking something very small, but with a telescoping stock and flush magazine with a spare built into the frame. Something like the Magpul Folding Pocket Gun would be about perfect, in a bottle-necked higher velocity PDW cartridge.

                                We don't need pistols for most of the duty positions that carry pistols, because pistols are about worthless for pretty much everyone in the military except investigators and a few units in the SOF community, and the modern handgun/sidearm needs to be brought into the 21st Century as well, not stuck in the rut of the 20th Century.



                                Last edited by LRRPF52; 01-30-2017, 05:29 PM.
                                NRA Basic, Pistol, Rifle, Shotgun, RSO

                                CCW, CQM, DM, Long Range Rifle Instructor

                                6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

                                www.AR15buildbox.com

                                Comment

                                Working...
                                X