Presumably you mean for AFV main guns:- The USA had an autoloading?/ autofiring 75 mm Sherman - but had problems with the feed, and Germany apparently had a sort of autoloading system planned for Panther II, based on the revolver magazine concept... Warships used a type of autoloading for the larger calibre guns AFAIK, and had done so for decades (hand-loading a 16" round is not really a viable proposition). There's nothing special about autoloading per se, any decent mechanical engineer should be able to come up with a system. It's a question of desirability and trade-offs in turret space/ habitability and round size. The majority of rounds in WWII were of a size to be handled relatively easily by the loader, an autoloader would have added cost and complexity (IIRC Sherman stabilisation systems were turned off as often as not because they were too "fragile" and took too long to set up for any worth to be had out of them from the crews' viewpoint).
Rats. I never thought of aircraft cannon. And the Molins 6 pr gun on the Beaufighter (test) and Mosquito (service) did as well. Nice one Christian
I've read somewhere that the german have a semi automatic loading system for one of their anti-tank gun
If it's a non-self propelled AT gun (ie a field carriage) that would have made it quite complicated. Where would the power source be? Unless the reference was a poor explanation of "semi automatic" which simply means that the breech opens on recoil (I think Tony Williams explained this in a different post - or it might have been on Tanknet). Yep, just found it on Tanknet: http://63.99.108.76/forums/index.php?sh ... ntry325741
Mounting an automatic cannon on an aircraft is practically simplier (forgetting the problems brought on by recoil of course) than mounting it on an cramped AFV, yes? The main problem I could see occuring would have something to do with elevating the gun and maintaing that the auto-loader is still in the right position for rounds to be delivered into the breech. AFAIR, this is one of the problems facing automatic cannons today. Let alone the problems that would trouble designers using 1940's equipment and technology.
The practical limit for autoloading in WW2 was the 40mm Bofors: the Germans did have a 50mm Flak 41 AA gun but it didn't work well. An conventional autoloading mechanism requires lots of space for machinery behind the gun breech. OK for an AA or naval gun - or even an aircraft gun - but a different matter in a cramped tank turret. Some modern tank guns have an autoloading system, but a lot of countries (incl the US and UK) don't bother. Tony Williams: Military gun and ammunition website and discussion forum
Didn't the Germans also field a semiauto mortar? IIRC, it was used in fixed fortifications, but I could be thinking of something else.
A good number of the tanks with auto loaders get round that by having the gun automatically reset to zero elevation so that the breech is lined up for the next round. Which causes problems with rate of fire and target-laying.
The Hs 129's 75mm cannon was not a very practical weapon, being that it only added more weight to an already overly heavy aircraft. Then of course the recoil which must have been a pain to work out. The Molins gun I'm not sure about, but I have heard it was rather successful (?).
The Molins gun was a good design (used in MGB's and Mosquito aircraft IIRC) but it was not used much AFAIK.
Hmm - I responded to this but the post seems to have disappeared. When I said that the 40mm Bofors was the limit for autoloading I was thinking about fast-firing automatics - sorry for the confusion. Tony Williams: Military gun and ammunition website and discussion forum