That seems unrealistic unless we improve our industry as it's already strained while producing existing designs.
Short term we could purchase mortars and artillery from someone (I am once again proposing the Canon de 75 modèle 1897) but long term we'd need to expand our industry if we want to domestically produce artillery or further develop our small arms industry.
Oh, strongly agreed, we should
not be producing artillery domestically at this point. Maybe in 5-10 years if things go really well for us, but for now, it's better to just purchase those things from abroad. Grenades are the one exception because I
think we should be able to produce them since we have a steel industry (for casting the grenade bodies) and are producing ammunition already (so we have a supply of explosives), but if not, then purchase those from abroad too.
Reminder we are not Czechoslovakia or say Sweden we simply lack a lot of the Technical expertise required in Actually designing automatic weapons. And us attempting to design a SMG is likely to end up with an extremely unreliable and expensive for us to Produce design
Blowback SMGs are mechanically very simple. You have a chunk of steel pressed up against the breech face, and its sheer mass holds it closed long enough to prevent case ruptures (and finding out this mass is as simple as putting an existing SMG's bolt on a scale). This chunk of steel moves backwards under the residual pressure of the combustion gases, opening the breech in the same way as, for example, a bolt-action rifle. After it reaches the backstop, a spring pushes it back forwards, and it chambers a round, again like a bolt-action rifle (and getting this to work is again a case of "measure an existing SMG, copy the dimensions used"). A raised bump on the front of the chunk of steel acts as the firing pin.
In terms of firearms, an open-bolt, fixed firing pin straight blowback SMG is about the easiest thing you can make. It's
easier to make than a bolt-action rifle; those have to worry about things like properly designed locking surfaces and stuff while a blowback SMG's equivalent is simply "did I make the bolt heavy enough?". The most difficult part is getting the magazine feed to work smoothly, but that's the kind of thing that we can do a straight ripoff of foreign designs on; there's plenty we could steal.
Legitimate question. What's the opinion on field guns for AT work? I ask because they have a longer shelf life than AT rifles and if we ever get armor they have some transferable lessons.
Edit:
On SMGs, we're screwed for something truly cheap at the moment. Almost every single interwar SMG is milled steel, with only the late 30s having stamped steel show up (The Sten wasn't really designed/implemented yet, and the other poster child the MP 40 isn't until after the MP 38, hell the grease gun isn't until like 43/44).
Field guns are basically the only "heavy " AT option right now, but they're expensive and difficult to transport around the battlefield. Our 13.2 mm machine guns are a lot more practical against what we'd be facing in the short term.
On SMGs, yeah, that's why we'd have to develop our own low-cost SMG if we wanted one. It is possible to make a milled SMG for relatively cheap (e.g., use tube stock for the receiver so that you don't have to do as much milling to get the overall shape, have a separate fire control group housing that's press-fit and tack welded into the bottom, minimize cuts in general), but few people in the '30s were concerned with "make gun as cheap as possible" which is why you see SMGs with select fire and bipods and adjustable sights that go out to 2 km and other silliness. If we establish a precedent of Reewiin trying to take other country's gun idea and then simplifying it as much as possible for cheap production with things like the Arisaka, I think we could also do the same with a SMG. Resistance groups in occupied Europe were able to produce SMGs with essentially zero industrial base, so I think we can too if we identify the need and our arms industry has spare capacity.
Honestly instead of SMGs we may do the far cheaper and technically demanding option of Adopting something like the High Power with a Pistol Stock. Sure it is not automatic, but for the soldiers we most likely would give a sidearm having a stocked pistol could be very much useful
A Hi-power is mechanically far more complex than an open-bolt SMG (it's a tilting barrel locked breech, so you need to have a system that'll precisely engage locking surfaces that are strong enough to withstand the force of firing while also keeping the barrel lined up accurately), not to mention that pistols are absurdly expensive for their capabilities - we'd be paying as much for stocked pistos as we would a SMG.
Edit: If you want to adopt a stocked pistol, let's start with a straight blowback pistol like the FN Browning 1910. We'll want to fire a larger cartridge than .32 ACP, so let's increase the mass of the slide to compensate. Semi-auto requires complicated disconnectors, so let's make it so that as long as the trigger is held down, it shoots, which simplifies the internal mechanics a lot. To reduce the rate of fire to something more manageable, let's increase the mass of the slide again, and strengthen the recoil spring a bit to improve durability. Give it a stock, a larger magazine, and let's remove some of those fancy machining cuts on the slide to speed production. We have now convergently evolved to the SMG.
