Gun drilling

I'm interested in what it takes to convert a normal industrialised economy into a wartime economy, both present and in the past.

My knowledge of production techniques made it quite clear that it takes little more than a CAD (computer added design) file and some paperwork to turn a normal metal works company into an arms or ammunition manufacturer. The one process which looked to be rather uncommon for civilian purposes, yet vital to arms production was as far as I can tell the production of barrels.

One of the appropriate production processes for this is gun drilling, and it doesn't seem to be so very much uncommon in civilian production as I believed until recently.

The interesting thing about it is that while gun drilling requires a specialised machine, all other works needed to produce an all-metal firearm can be done on a single multipurpose, multi-tool machine (CNC machining centre). The CAD file, a gun drilling machine, a multi-purpose metal works machine, power supply and a roof are probably all that it takes to start a rifle factory nowadays. It's no wonder that so many companies have begun producing AR-15 rifles during the last years of irrational demand. It doesn't take much to set up such a company with its own production capacity and the profit margins were ridiculous.

It makes sense to outsource the stamping jobs (stamping is superior to milling for many parts) and the plastic parts production to other companies, of course. The bad thing about the plastics and stamped parts is that the tool (negative shape) is relatively expensive and more difficult to produce than the part itself.

I've found some nice info about the gun drilling technology, maybe someone else is interested, too:

A funnier, older video:



  1. Since nowadays you can google the places of many factories and shops, during wartime what measures do you think would help keep your machines safe? I believe that part of what it takes to convert a normal industrialised economy into a wartime economy is protecting what you have.

    In a wartime scenario do you consider the use of EMP or you don't consider the use of such weapons in the wartime due to having a low probability in most wartime scenarios or for some other reason?


  2. Such machines are -save for the computer part- robust. You'd need an almost direct bomb hit to take it out permanently.
    Back in WW2 the U.S.A.A.F. poured 500 lbs general purpose bombs on German ball bearing factories. The collapsed roofs were removed and the machines restarted.

    Germany has too many small and large factories to take out - other means of attack would be much smarter. Electricity grid nodes and classic powerplant's steam turbines, for example. Large factories of old had their own powerplant, but the move from turnover tax to value-added tax dissolved such vertical integration since the 70's; today's metal workshops and factories don't even have emergency diesel units.

    Btw, my interest in conversion to wartime economies should also be understood in the context of the short high intensity arms races that preceded both World Wars in Europe (1912-1914, 1938-1939).

    1. Btw, my interest in conversion to wartime economies should also be understood in the context of the short high intensity arms races that preceded both World Wars in Europe (1912-1914, 1938-1939).

      These arms races are very interesting. Do you recommend some sources/readings on them?

  3. Isn't rifling the more uncommon process?
    Manufacturers of barrel forging machines are super rare, while those may be usable for other production processes, those are limited
    I can't imagine any other purpose of of button rifling.
    That leaves cutting. While obviously the most general process, i'm not sure wheather common machinery usable for this (in desired quality at least)

  4. Operation Chastise from WWII, using that you could cause major damage though flooding, would cause power loss as well. Didn't know about the powerplant problem in Germany, interesting fact to know.

    More like from your "Elegance in warfare" post


    To quote,

    "You're a strategic air war planner. Your enemy has 1,000 trucks, one oil refinery and one truck factory producing 100 trucks per period. You can order two air attacks, strong enough to take out either refinery or factory each. What are your orders? You could bomb only the truck factory, but the 1,000 trucks would still serve your enemy.
    You could bomb only the oil refinery and the 1,000 trucks would soon become useless. In fact, the production of additional trucks would become pointless. Do you order to bomb both? That would certainly make no sense. You should omit the bombing of the truck factory and just bomb the oil refinery."


    1. This elegance makes sense if the enemy can't rebuild the refinery, but these wartime economies were more resilent systems with much ingenuity. Attacks did not empty capabilities, but forced them on a more difficult to maintain level with short-term shortages.

  5. Obligatory link : the Kel-Tec CNC company


    It designs and mass manufacturates weapons for the civilian US market, and it very much what you described.

    Regarding CNC, though, in practice it is as you say, but in practice there are a vast number of intricacies that require schooled and skilled personnel. These technicians are hard to come by, since the prequirement is to have a good set of skills as mechanic / metal worker ("Schlosser", in German) and those are already too few.

    Rather than bomb the factory, if the enemy could arrange the physical elimination of those skilled technicians, the CNC machines would be much less useable.

    My main concern about industrial warfare is that it is too fragile. I just finished reading about the First French Army (1943 - 1945) and the logistics already where nightmarish. Often exploitation was denied internally, due to lack of fuel, transportation etc.

    We have to assume that the next conflict of importance will see the denial of fuel and energy. Denial of transport infrastructure would be comprehensive as well. We have to remember the Exodus of 1940, clogging all french roads, and used to maximum effect by Germans.

    The western campaign of spring 1940 is the only configuration that is close to our present situation, regarding dense population centers, availability of cars etc. Now that 75% of Europeans live in an urban environment, it is to be worse that that actually.

    Fall Barbarossa or North Africa are exotic engagements, when refering to the home european theatre. A conflict in Europe might look more like the Battle of Normandy, which lasted more than two months in a very restriced area with few fuel & transportation and logistical bottlenecks.

    So the "war economy" aspect is as you said in the comments best viewed in an interbellum period, but once the conflict is on then it cannot be as critical.

    The Lee-Enfield stories about Afghanistan make a lot of sense in that context...

  6. What about the production of artillery and tank gun barrels? AFAIK there are only a few places in the world that are set up to produce them. I'm not even sure if there's a factory in the United States with the necessary equipment.

  7. I think metal works could be handled, provided all the right alloys are at hand.

    But the semiconductor stuff (sensors for example) is a real pain to expedite and expand!

    1. ...as was automotive production a few generations ago. the solution: Commandeer civilian equipment, let the soldiers improvise with the variety of equipment.