WesWorld

I invite your OOC comments

Quoted

Requests for proposals to industry regarding designs to utilize the recently approved 7.92x45 intermediate cartridge received a number of responses. In addition to a proposal from the Gustloff-Werke to convert and adapt the Heer’s Selbstlade Gewehr G5 to fire the new cartridge three new designs were submitted for evaluation.

Industriewerke Karlsruhe Karabiner 04

Derived from the G5 design and sharing its action. Semi-automatic only.

Weight: 4.14 kg
Length: 1,005 mm, 1,205 mm
Barrel length: 520 mm
Cartridge: 7.92x45mm
Action: Gas-operated, semi-automatic
Rate of fire: 25 rounds/min (practical)
Muzzle velocity: 760 m/s
Effective firing range: 650 metres
Maximum firing range: 1,200 metres
Feed system: Clip-fed, staggered-column, 10 or 20-round detachable box magazine
Sights: Open iron sights graduated from 100 to 900 m



Walther-Werke Maschinenkarabiner 05

A new design using a conventional tilting bolt action; capable of both semi-automatic and automatic fire.

Weight: 4.6 kg (unloaded with magazine)/ 5.13 kg (loaded)
Length: 940 mm
Barrel length: 420 mm
Cartridge: 7.92x45mm
Action: Gas-operated, tilting bolt, full auto or semi-auto
Rate of fire: 550–600 rounds/min
Muzzle velocity: 760 m/s
Effective firing range: 300 metres (automatic) 600 metres (semi-automatic)
Feed system: 20 or 30-round detachable box magazine
Sights: Adjustable sights, rear: V-notch; front: hooded post



Mauser-Werke Maschinenkarabiner 06

A new design, incorporating a novel action. Capable of selective fire – single-shot semi-automatic, three-round burst, or full automatic.

Weight: 4 kg (with empty magazine)
Length: 940 mm
Barrel length: 419 mm
Cartridge: 7.92x45mm
Action: Roller-delayed blowback
Rate of fire: 350–450 rounds/min
Muzzle velocity: 760 m/s
Effective firing range: 300-450 metres
Maximum firing range: 800 metres
Feed system: 30-round detachable box magazine
Sights: Rear: V-notch; front: hooded post

For a moment I thought these were assault rifles until I saw the ammo and then went derp.

To say the truth my favourite is the Mauser-Werke Maschinenkarabiner 06 (man that is a mouthfull) if only because it is lighter and it has a pistol grip ... also because I like the AKM.

Quoted from "Doorcf"

For a moment I thought these were assault rifles until I saw the ammo and then went derp.

They are assault rifles, actually - 7.92x45 is an intermediate cartridge. The pictures are somewhat tricksy, since they show weapons chambered in 7.92x33 Kurz. The 7.92x45 round would increase the width of the magazines and the visual length of the weapon...

The MV on the last two rifles is probably a bit high; I'd expect it to be more in the 680 m/s to 710 m/s range.

The Karabiner 05 is the best weapon of the three, but also just as obviously not going to get selected.

I have no technical comments, I'll defer to Brock who is this forum's small arms expert.

Brock wrote,

Quoted

The MV on the last two rifles is probably a bit high; I'd expect it to be more in the 680 m/s to 710 m/s range.

I'm not the firearms expert so I will ask - if the cartridge being fired is the same why would the muzzle velocity be different? Could it possibly be a function of barrel length?

Quoted from "BruceDuncan"

Quoted

The MV on the last two rifles is probably a bit high; I'd expect it to be more in the 680 m/s to 710 m/s range.

I'm not the firearms expert so I will ask - if the cartridge being fired is the same why would the muzzle velocity be different? Could it possibly be a function of barrel length?

Yes, that's correct. The longer a bullet stays in the barrel, the higher the velocity as it exits the muzzle. Some aspects of the firearm design can change that, however. You can hot-load the cartridge (place more propellant in the casing) to compensate, but that's not always the best or safest solution. For small arms, particularly assault rifles, high MV isn't *always* good, since it's part of the system of feedbacks that results in recoil and felt recoil.

The same principle works for naval guns, which is why you see the length of naval cannon rising from, say, 12" / L35 guns and steaming merrily onward to 12" / L50 guns, which have superior MV and therefore range, accuracy, and armour penetration values...

I'm not enough of a ballistics person to be able to calculate the MV for a fictional cartridge fitted to a rifle, and so my best guess would put MV for the MK-05 and MK-06 in the 680-710 m/s range. You could maybe go as high as 730 m/s, although I'd advise against it. The shorter barrels will lower the MV by a significant percentage. I'll note, before the question arises... the MK-05 / 06 have barrels that are ~80% the length of the K-05, but I'm fairly certain your MV doesn't follow the same curve relative to barrel length. In other words, I don't believe the MV will necessarily be 20% less even though the barrel length is reduced by 20%. (Although I would again note that I'm not a ballistics expert, merely an aficionado.)

My best advice would be to set the MK-05 / 06 MV at around 690 m/s, which is approximately 90% that of the K-05. Since the K-05 is based on a historical rifle firing an almost-identical cartridge, I wouldn't change the specs on that at all. It's 50 m/s higher than the historical StG-45M with the 7.92x33mm Kurz, with the increase being down to the longer / more powerful cartridge case...

It's a pretty nitpicky little detail, but I hope that helps.

Quoted

The pictures are somewhat tricksy, since they show weapons chambered in 7.92x33 Kurz. The 7.92x45 round would increase the width of the magazines and the visual length of the weapon...

I was thinking the same thing... It makes it even more apparent as the IKK 04 magazine is visually wider than the magazines of the WWM 05 and the MWM 06. Also, the WWM 05 and MWM 06 are the same length so size-wise the way they are shown above should be how they actually are compared to each other if you had them in your hands... but then compared to the MWM 06 image, the magazine for the WWM 05 looks more like a 10-round magazine than a 30-round or 20-round magazine.

Yes, the MK-05 does have a ten-round magazine in the photo.