This page started off with someone suggesting that armoured vehicle crews should be issued the H&K P7 PDW. The P7 is still in development, looks like it will be very high tech and uses a new 4.6mm round that sounds like it has the same characteristics as the FN 5.7mm low recoil, good autofire controllability, high penetration against soft body armour and, not to put too fine a point on it, negligible incapacitation.
I'd rather have something like a .45 MAC 10, I commented. Equally compact but easy and cheap to manufacture and using a readily available round of proven effectiveness. If you have to defend your vehicle against infantry you can't always stay buttoned up. Sometimes the only option to resort to auxiliary weapons. Weapons such as the M3 Grease Gun and M4 carbine are fine for dismounted use and should still be carried by vehicles, but a little too big for quick pop-up shots from a vehicle hatch. .45 pistols are good, but it would be useful to have something a bit more.
I've suggested the MAC10 or one of its clones, but this weapon is not perfect. Main objection is the very high rate of fire that can empty a magazine in a second and a half or less. It would be nice to reduce the cyclic rate without having to resort to complicated devices such as burst fire mechanisms. One idea suggested by my friend Ed was to use the proven mechanism of a two part bolt. The section of bolt with in contact with the breech has to move a larger bolt, and this mechanical disadvantage slows the action down. This device may also have applications. Another idea that may be used instead of or in addition to the above mechanism is to build a machine pistol using Gas-delayed blowback. This system has been used in weapons ranging from pistols to assault rifles. A small volume of gas is vented from the barrel into a side chamber. In the forward part of this chamber is a piston linked to the bolt or slide. The pressure of the gas retards the recoil movement of the bolt. After the bullet leaves the muzzle the pressure decreases as it equilibrates with the dropping pressure in the barrel and the bolt begins to move rearwards. This sequence is reminiscent of how a fume extractor/bore evacuator of a tank gun works.
Possibly a gas delayed blowback mechanism could also reduce the build up of fumes when a machine pistol is used inside a vehicle a welcome bonus.
Features of the Tanker Machine Pistol.
Weapon should be compatible with various designs of vehicle firing port. This may require the barrel to project for several inches ahead of the receiver, and this feature may have other applications such as grenade launching.
.45 calibre for good incapacitation and simpler logistics. It seems likely that the .45 pistol will see a renaissance in use. In many applications it never went away. The .45 is less likely to damage lightly armoured friendly vehicles when "Backscratching" and a few steel cored AP rounds in the magazine can deal with any soft body armour.
It would be useful if the machine pistol can use handgun magazines as well as its own large capacity magazines. Which magazine it is compatible with will depend on which .45 pistol is adopted, but I'd personally go with the Glock .45 pistols, but there is also a case for the SOCOM Mk 23 Mod 0
A brass catcher for when firing inside a vehicle would be another useful feature.
Ed commented on this idea:-
"Make a million. Every armored trooper will want one slung under his arm; it's the cheapest life insurance money can buy."
It is also perhaps inevitable that infantrymen will borrow the machine pistols for house clearing operations or investigating tunnels and sewers.
An interesting accessory for the tanker machine pistol might be a revival of the Krummerlauf bent barrel device.
A similar device was also tried for the M3 grease gun but the tanker machine pistol will offer a far more manageable package to be used from inside a vehicle. This might include an additional fume expansion chamber and a prismatic sight. Not only would this be useful for tank defence, but also firing round corners in house to house fighting. One of the original purposes of the bent barrel was to fire out of trenches without getting shot in the head -should work form a AFV hatch too. I'd suggest a 45° angle to the barrel attachment. If the machine pistol is held at a low assault position and aimed upward this will make the final section of the barrel horizontal at eye level and so can be armed at targets ahead of the firer without needing to remove the device.
Alternatives It may be that tankers could be issued a compact weapon along the lines of the Olympic Arms "Pistols". These have a method of operation and many parts in common with the M4/M16. Since FMJ 5.56mm ammo is not that effective when fired from a short barrel the calibre will be 9x45mm. This poses the interesting question as to what would happen if a magazine of 5.56mm rounds was fired. Would it damage the weapon or would the bullets have greater effect due to their yawing?
Another potential weapon is a Mauser Broomhandle type weapon loaded with the .45 Springfield Magnum round that I have suggested.
FEEDBACK Veteran Tanker Ralph Zumbro writes:- There were many times we could have used an SMG with a grenade launcher, especially for dismounts. Snipers in trees and windows come immediately to mind. You don't have much time to nail them. We normally kept an SMG next to each hatch for anti-sniper work. Sometimes you'd be poking around a vill and get shot at and get only a puff of smoke or a sound direction. Being able to put a WP grenade as a marker for the 90mm would have been a help.
A simple compact SMG such as the tanker machine pistol would be idea to position by vehicle hatches. Having a rack of MP launchable rifle grenades beside them makes sense too. These would be a simple "Bullet thru" design that could also be hand thrown, and probably available in both Frag and WP.
I would really like to see something like the Vichr or the 7-9 x 45mm developed as a compact 9x45mm tanker's weapon as it is the best I have yet seen. I can still shoot well enough to give creditable demonstrations. THAT WEAPON IS IT. That is the perfect close combat weapon, backed up by the multi-shot revolver 40mm and a sniper version, you could literally destroy most other units in urban and jungle fighting. I'd give one to every crew member. They are just small enough to hang on a baldric or Sam Browne type body harness. I'd still like to keep the bullet capture launcher, as I suspect it would have better range than a stubby under barrel launcher. Give them to the dismounts from the Bradley and also build a firing port version. For city work. I'd suspect they might be a good Coax weapon. One reason, of course, is to keep the ammo selection down. We had a way of carrying the old M-1 carbine that was FAST. We simply imbedded a screw-eye in the left side of the stock, near the trigger guard. Next a GP strap was attached and slipped over the left shoulder, like a baldric, leaving the carbine, which by that time had had its buttstock sawn off, hanging at the right hip. Some guys put a light string from the screw-eye to the pistol belt to eliminate swinging. The result was what we called the "Whippit" because all you had to was shove down with your right hand and whippit out, shooting. I have also seen a carbine with a stud embedded in the stock, which fit a clip on the pistol belt
UPDATE Sadly M16 magazines can't be relied upon to handle .223 cases with bullets of more than 7mm calibre, so the 9x45mm and 7-9x45mm are not practical unless special magazines are issued. Having a compact weapon using the 9x39mm round is still possible, as is a weapon in the 6.8x43mm or .270 ARC chamberings.
Stan's idea of a 7-7.5mm bullet in a 9x19mm case makes far better sense than the 4.6-5.7mm rounds proposed by HK and FN. The .224 BOZ, using a 5.56mm rifle bullet in a 10mm Auto Pistol case also looks like a more sensible policy than the 5.7mm or 4.6mm. The Beretta MR93R is close to what Stan proposed (and shares parts with the M9), but Stan has found that it jumps too much on burst fire. Kept on semi-automatic, or fitted with a more modern muzzle brake it might be what he wants. So too might the Parker Hale IDW, although .45 would be better.
An even better option might be to issue a long-barrelled .45 pistol based on the Glock, HK Mk23 or a high-capacity version of the M1911.
By redesigning the grip scales a retractable wire stock that fits flush with the backstrap should be possible. Fired from a 7 barrel the .45 Super round reaches 1275fps, which gives us a momentum of 1.3 ftlb/sec and a TKO of 18.9. Compare this to a 124gr 9x19m at 1200fps (0.66 ftlb/sec, TKO=7.5) or a 62gr 5.56mm fired from a rifle at 3100fps (0.85 ftlb/sec, TKO= 6.2). Standard 230gr .45 ammo should produce at least 1045fps from a 7 barrel, giving 1.07 ftlb/sec and TKO= 15.5 -still a significant improvement.