# AA / AT Guns



## stug3 (Jul 24, 2013)

2cm Anti Aircraft gun in Russia, 1943


----------



## stug3 (Jul 24, 2013)

On an M3 Stuart chassis










M8 Armored Car


----------



## stug3 (Jul 24, 2013)




----------



## davebender (Jul 24, 2013)

Sd. Kfz. 7/1












About 800 produced with flakvierling and 1,000 produced with 3.7cm flak. 

Germany used many make shift SP flak such as captured enemy tank with flakvierling ILO turret. Sd.Kfz.7/1 and Sd.Kfz.7/2 were closest thing they had to a standard purpose built weapon.


----------



## fastmongrel (Jul 24, 2013)

Morris C9 self propelled Bofors


----------



## davebender (Jul 25, 2013)

Typical make shift German SP flak vehicle. Captured tank probably had a damaged turret but was otherwise operational. Field workshop pulled turret off, mounted flakvierling (i.e. quad 20mm) and fashioned gun crew protection using RHA plates salvaged from destroyed Sd.Kfz.250 or Sd.Kfz.251 APC. This vehicle is a relatively well designed conversion so it was probably done in army rear area. Conversions accomplished by division workshops would be more crude.


----------



## stug3 (Jul 25, 2013)

This thing looks like it could cause some serious damage.










Did they really need 4 guys in that turret?


----------



## davebender (Jul 25, 2013)

Were guns magazine fed? If so you need additional people to keep changing magazines.

That's what I've never understood about flakvierling. Why didn't Germany make a belt feed for Flakvierling? Eliminate two loaders and flakvierling mount would probably fit on smaller / less expensive Sd.Kfz.251 APC.


----------



## Gnomey (Jul 25, 2013)

Good stuff!


----------



## davebender (Jul 25, 2013)

HyperWar: The Machine Gun (Vol. I/Part V)


> The Germans have long been famous for using a reliable firing mechanism in every conceivable manner in which it could be applied and the MG-151 was certainly no exception. It made practically a simultaneous appearance as an antiaircraft automatic gun and was given the designation of Flak 38. This cannon was designed by Mauser engineers, Linder and Froebel, and although similar in appearance and identical in operating principles, it is a distinct weapon and not to be confused with the MG-151 20.



If 2cm Flak 38 was designed by same people as MG151 and employs identical operating principles then why doesn't the weapon have a belt feed similar to MG-151? Larger 3cm Mk103 cannon employed belt feed so it cannot be because 20mm x 138mmB cartridge was too powerful for belt feed.


----------



## Shortround6 (Jul 25, 2013)

davebender said:


> Were guns magazine fed? If so you need additional people to keep changing magazines.



The 40mm was feed by clips. 4 rounds to a clip like big rifle stripper clip except the Bofors gun took the rounds out of the clip it self and dumped the empty clips out the bottom. It was possible to stick in two clips, one above the other or even start with one 4 round clip, 2 loose rounds and a second 4 round clip just barely in the feed way/guides. Since the gun cycled at about 3 rounds per second a loader per barrel were pretty busy men. 



davebender said:


> That's what I've never understood about flakvierling. Why didn't Germany make a belt feed for Flakvierling? Eliminate two loaders and flakvierling mount would probably fit on smaller / less expensive Sd.Kfz.251 APC.



If they could have a made a belt feed Flak 38 you wouldn't need a flakvierling, just make a twin mount with belt feeds. If you could keep the barrels cool the cyclic rate of fire and the practical rate of fire would be a lot closer. Cycle rate of the twin would be over 800 rounds per minute as long as the belts held out unless the belt feed really slowed the gun down.


----------



## stug3 (Jul 25, 2013)

davebender said:


> Were guns magazine fed? If so you need additional people to keep changing magazines.
> 
> That's what I've never understood about flakvierling. Why didn't Germany make a belt feed for Flakvierling? Eliminate two loaders and flakvierling mount would probably fit on smaller / less expensive Sd.Kfz.251 APC.



Yes, the Bofors 40 mm was magazine fed for the most part. I think some post war naval variants had some kind of mechanised feed but not belt fed.

The M19 was built on the M24 Chaffee chassis, the post war M42 Duster was built on the M41 Walker Bulldog chassis.

M42 Duster


----------



## davebender (Jul 26, 2013)

I agree. However they might want four anyway. Fire two at a time and cooling problems should be minimal.






Personally I like the Italian Sidam turret design. Small one man turret containing only gunner. Belt fed weapons located outside turret. Small size makes it possible to provide turret with decent armor protection. Cannon receivers located outside turret would be protected only against small arms fire.


----------



## Shortround6 (Jul 26, 2013)

Germans _may_ have stopped work on a Belt feed Flak 38 because they were working on mounting the MK 103 guns on the Flak 38 mounts.


----------



## davebender (Jul 26, 2013)

Heer have preferred 20mm automatic cannon from 1915 right up to the present day. Otherwise armored vehicles from Panzer II through Marder IFV series would have 30mm autocannon rather then 20mm autocannon. I cannot explain this preference but I think we can rule out plans for a switch to 30mm.

German navy was a different matter. They wanted twin 30mm light flak on U boats. Perhaps it's because they had to deal with B24 bombers and other such large aircraft attacking at low level.


----------



## Shortround6 (Jul 26, 2013)

Rheinmetall had a contract for 2000 guns and Gustloffwerke of Suhl and one for 1000 guns, all to be completed by March 1945 although it is doubtful anywhere near that many were finished. Mauserwerke and a model of their own as did Brunserwerke. A limited number of 3cm flakvierling 103/38 were also made. The Guns were a bit too powerful for the mount/s and excessive vibration hurt accuracy, even after the sight was given a spring suspension.


----------



## davebender (Jul 27, 2013)

> Rheinmetall had a contract for 2000 guns and Gustloffwerke of Suhl and one for 1000 guns


Were those army or navy contracts?

November 1943. 287 x Type XXI submarines ordered.
Each boat was supposed to have 4 x 30mm AA guns
.....Two twin turrets.
1,148 30mm autocannon required for Type XXI submarines.

German Schnellboot carried autocannon up to 3.7cm in size. I'll hazard a guess the high tech stabilized LM44U twin turret designed for Type XXI submarine was also intended to replace 3.7cm single mount on S boats. Germany built 230 S boats and had hundreds more on order. 

German navy ordered 15 Flottentorpedoboot 1939 class. Each boat originally equipped with 4 obsolete 3.7cm C/30 weapons. Another good candidate for the LM44U twin 3cm turret.

These installations only scratch the surface of naval requirements. Most German naval vessels completed prior to 1942 had obsolete 3.7cm C/30 weapons which must be replaced.


----------



## Civettone (Jul 28, 2013)

davebender said:


> I agree. However they might want four anyway. Fire two at a time and cooling problems should be minimal.


That is how the Flakvierling worked. It fired two guns at a time. Firing all four was exceptional.



> Personally I like the Italian Sidam turret design. Small one man turret containing only gunner.


If you do not have a gun laying calculator or FCS, you need to have a couple of extra men for spotting and range calculation. And of course elevation and traverse were operated by two different men.

Kris


----------



## Shortround6 (Jul 28, 2013)

davebender said:


> Were those army or navy contracts?
> 
> November 1943. 287 x Type XXI submarines ordered.
> Each boat was supposed to have 4 x 30mm AA guns
> ...



The 30mm guns intended for the S boats and MK XXI subs were the Kreighoff 30mm MK 303 gun which used a different round than the MK 103, a 30mm X 210 case instead of 30 X 183B and about 9-10mm fatter through the body of the case, ammo and the guns used to develop the post war Czech M53 gun and ammunition. 

Looks like the MK 103 guns were mostly for the army, although some Navy use was probably intended as the Navy used it's share of MK 38 guns.


----------



## davebender (Jul 28, 2013)

Person operating rangefinder doesn't need to be in gun turret. Could be vehicle commander located in his own cupola.

While stationary the vehicle driver could serve as a spotter. Or you could have a dedicated spotter in his own cupola. All connected by vehicle intercom so you don't need to be in physical contact.


----------



## stug3 (Jul 30, 2013)

Heavy flak guns firing at Soviet tanks, July 1942


----------



## davebender (Jul 31, 2013)

Same highly effective 20 x 138B cartridge as German Flak 38 but much higher rate of fire. Was this light AA gun any good?


----------



## Shortround6 (Jul 31, 2013)

As with a lot of things _it depends._

Effectiveness of AA guns has a lot to do with both mounts and sights in addition to the gun itself and leaving ammo out of it. 

going by Wiki. the rate of fire was often de-tuned to about 360rpm per barrel. But since this was the _only_ Multi barrel 20mm mount the Finns had the mount's rate of fire was higher than anything else. No comments about the mount in action although towing was a bit a of a problem. There were complaints about the sight. How much the sight affecting things may affect the entire system.


----------



## Juha (Jul 31, 2013)

From the excellent Jaeger platoon site:
"When Finnish Armed Forces re-estimated the antiaircraft-weaponry left from the war 20 ItK/40 proved to be only 20-mm AA-gun, which was still satisfactory. The guns remained in training use until 1970's and even that remained warehoused for possible wartime use until 1980's."

FINNISH ARMY 1918 - 1945: ANTIAIRCRAFT GUNS PART 1, roll to the bottom of the page but the page is full of interesting info on 20mm AAA guns used by Finns.


----------



## stug3 (Sep 7, 2013)

German Gebirgsjäger operating a 2 cm anti-aircraft gun in the Central Caucasus near Teberda, September 1942. 






German anti tank gun, Russia 1943


----------

