The Great Debate: The Case Against
By Bob Patrick

As regards the 20mm cannon argument the weapon on the Mk II only fired solid shot according to my book and the maximum effective range was 650 metres. I believe that the rate of fire quoted is cyclic and would apply if belt fed I cannot believe that anyone could fire off 10 rounds and reload in 2 seconds which is what is implied by the Forty book. The rate of fire of a Tommy gun is 450 rpm but not if you have to reload 30-round clips during that minute. Also if firing the gun at infantry along with co-axial MG I can't see anyone able to reload at all if any kind of sustained fire was to be attempted.

Plus what annoys me about the whole thing is that most MGs had a rate of fire of 550rpm plus and they are less effective vs soft targets if vehicle mounted than a poxy 20mm solid shot with a magazine feed. Especially true for the HMGs mounted on vehicles such as MkVI light tank.

At best I believe the gun on the PzII should be treated as a class 5 AT rifle that doesn't get the benefits of 'no penalties for movement' and say an 8-point weapon if stationary and 5 point if moving to represent both gun and MG firing and I think that is overly generous.

Below is a table of the somewhat pathetic capabilities of the 2cm round, please note 1939 round, lucky to be a class 6 gun let alone class 5 especially in 1939.

Penetration of Armor Plate at 30 degrees from Vertical
Ammunition	100m	500m	1000m	1500m	2000m
Panzergranate 39	20mm	14mm	9mm	0mm	0mm
Panzergranate 40	49mm	20mm	0mm	0mm	0mm
Pzgr.39 (APCBC) - Armor Piercing Composite Ballistic Cap
Pzgr.40 (APCR) - Armor Piercing Composite Rigid (Tungsten Core)

The Great Debate: The Case For
By Rolf Hedges

1) "The Panzer 2 used the 2cm kwk 30 or kwk 38, -- both were adapted from the 2cm flak 30 or 38 -- neither differed materially from their flak gun relatives, althought the kwk 38 had a higher rate of fire - both were automatic magazine loaded weapons - as mounted in the 4, 6 and 8 wheeled a/cars."
--from German Tanks of WW2 by Chamberlain and Doyle

AUTOCANNON surely ??

2) From German Tanks of WW2 by George Forty

the 2cm kwk 30 had a rate of fire of 280 rounds per minute, it was fed by 10 round magazines, of which 18 such magazines were carried (180 rounds).

Also an extract from the German Panzerztroop regulation handbook 1939

"enemy tanks should be engaged from static fire positions at 600 metres, ..... short bursts of 2/3 rounds should be fired at targets from fire positions or on the move. Canon and MG fire can be used simutaneously against gun crews or troop concentrations..."

3 ) From Ian Hogg, German Artillery and Guns of WW2

"the 2cm kwk used a box mag and was recoil operated -- it was really an overgrown machine gun firing from an open bolt -- it had 2 triggers, the left trigger gave automatic fire, the right gave single shots various rounds were available;

1) HE shell with self destroying tracer
2) as above with explosive/incendiary filling
3) AP shell /he/incendiary shell
4) AP shell with tungsten core

Hogg lists the rate of fire as 280 rpm cyclic, 120 rpm environmental / practical

At the end of day the gun is not a load em, aim and fire gun its a slightly better than HMG, with a slower rate of fire.

At the end of the day surely more autocannon than cannon ?????

Other German vehicles using the 20mm cannon

The Sdkfz 250/9 neu, and the Sdkfz 234/1 AFV's used a modified turret akin the the 222 turret. The 20mm gun was adapted to take 20 round mags, the 20mm and mmg could be fired from a 2 levers hinged to the elevation and traverse wheel. The vehicles carried 24 20 round mags