Roller delayed blowback invented pre-WW2, influence on post-war small arms?

Discussion in 'Alternate History Discussion: After 1900' started by wiking, Apr 17, 2019 at 9:25 AM.

  1. wiking Well-Known Member

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    Jan 19, 2006
    What if Mauser has been able to invent the roller delayed blowback system that they had developed during WW2 IOTL before the war and produced a series of widely used small arms based on the concept during the war? How would it influence small arms designs post war?

    Here are some examples of firearms that used the system from the 1940-early 1950s IOTL:
    https://en.wikipedia.org/wiki/MG_45
    https://en.wikipedia.org/wiki/StG_45(M)
    https://en.wikipedia.org/wiki/CETME_rifle

    Since the Allies were influenced by German small arms designs from WW2 how would even lighter, less expensive, and effective small arms have influenced European (Soviet and NATO) and US designs after WW2? I know the Soviets experimented with the level delayed concept and produced a very interesting version of the AK47, but ultimately decided not to adopted it for some reason:
    https://en.wikipedia.org/wiki/TKB-517

    The French did of course adopt a whole series of arms around the level delayed blowback system:
    https://en.wikipedia.org/wiki/Blowback_(firearms)#Lever-delayed

    The US though never seemed to develop any military small arms with a similar idea. They did test the CETME rifle in the late 1940s, but since it was still a relatively unproven and radical concept and of course not an American design they did nothing with it. They did however adopt the M60 based around parts of the FG42 and MG42...if something like the MG45 was instead the Wehrmacht mainstay and the FG42 was effectively the CETME rifle might the US adopt an MG and/or rifle around the same idea? If so would it be better than what they used historically, as the Bundeswehr got good use out of the idea with the G3 and HK21, as have several other militaries who ended up using it in conflicts from the 1960s on. The HK21 even ended up about as light as the legendary PKM, so potentially something like it could have been an effective counter to it in the conflicts the US ran into in rough terrain than the M60 and M240, which have proven too heavy to lug around on foot.

    Thoughts?
     
  2. Orcbuster Well-Known Member

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    Mar 6, 2017
    Roller delayed blowback wasn't a revolutionary concept in any way. It was just the system the germans landed on because it was one of the few system that did not require there to be a hole drilled in the barrel for the gas system which they were fervently against. Rest the world made do with long stroke/short stroke pistons still used today etc and did fine.

    Problem with roller delayed blowback is its inflexibility in the ammo powder loads it will accept and violent extraction which has a tendency to mess up brass for reuse.
     
  3. wiking Well-Known Member

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    Jan 19, 2006
    Uh, no. The origin was an outgrowth of working on the roller locking system being working on for a semi-automatic rifle (gerät 03 and 06) both of which had gas pistons and holes drilled in the barrel (source: "Full Circle: a treatise on roller locking"). By the point it was developed the German army had gotten over the hole in the barrel phobia. It offered the advantage of being able to omit the gas piston system and there save a lot of weight and complexity and therefore expense and manufacturing time. The use of the gas piston system by most other nations was a function of multiple factors. You're right in the sense that different delayed blowback systems already existed at the time (Pedersen device/rifle for instance), but no one had used rollers with inclined recesses before to achieve that effect, which made it much less complex and costly to make properly once the necessary mathematics had been worked out regarding the pressure curve of the ammo.

    The 'problem' of ammo load didn't seem to be an issue for the Germans in WW2 as they developed the system, nor after the war either. The Soviets apparently feared they'd run into the problem of powder consistency, which may have led to the rejection of the TBK-517. It isn't cited as an issue though for the Pedersen rifle, despite using a delayed blowback system; the Army was just concerned about the waxed ammo cases and potential for dirt, dust, and mud to get into the system. Fluting the chamber would have solved that perceived issue. The fluting is what messes up brass or steel, but since armies didn't reload used cases that wasn't/isn't an issue, that's a problem for civilians who reload to save money. The virtue of that sort of extraction is that it is extremely reliable and works no matter how dirty.
     
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  4. Orcbuster Well-Known Member

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    Never done brass policing through the woods have you? We did that all the time through training areas filling crates of the stuff.
     
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  5. wiking Well-Known Member

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    Cleaning up brass is one thing, reloading it is another. Especially as we are taking about 1950s-60s practice, not modern ones.
     
  6. Orcbuster Well-Known Member

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    You mean like when the US had 6 divisions pick up all the brass at Okinawa after the battle?
     
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  7. wiking Well-Known Member

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    Do you have a source on that? I have never heard of that happening and details might be helpful.
     
  8. Orcbuster Well-Known Member

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    This was fairly standard practice of all armies at the time. There were specialized units whose job it was to scour the battlefield of anything valuable from vehicle wrecks to bullet casings. In general there was a fairly sized industry of its own consisting entirely of this. Here is a German POW cleaning out cartridges in belgium in 45.

    [​IMG]

    This is one of those menial duties in the military that you don't hear much about until you've actually experienced it. Its certainly not a new practice. The okinawa incident is a bit special since the commanders had combat units do it right after the battle which they were fairly pissed off about. Detailed in "With the Old Breed" by Eugene Sledge.
     
  9. wiking Well-Known Member

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    Jan 19, 2006
    Sure to recycle the materials for other use, not to reload AFAIK. Europe in 1945 though was a special situation given the raw material crisis.
     
  10. Orcbuster Well-Known Member

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    Reloading is recycling. Casings in good condition were absolutely reused by manufacturers. UK did it because you can find shell casings with up to three to four separate manufacturers proof marks around flanders.
     
  11. Peg Leg Pom Well-Known Member

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    Oct 18, 2009
    Were they reloading, or melting down the brass though?
     
  12. longsword14 Communism: This time, we will get it right!

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    Jan 16, 2015
    And war ammo might very well be steel cased. Works well for delayed blowback guns.
    Brass scraping might also be an American habit.

    The advantage/disadvantage of delayed blowback over gas is small enough that widespread adaption comes down to who manufactures it ( native manufacturers are preferred ) and how early the gun is adopted. The Germans adopted, then unadopted the FAL in favour of the G3.
     
    Last edited: Apr 17, 2019 at 12:52 PM
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  13. tomo pauk Well-Known Member

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    Jan 20, 2016
    ??
    Reloading is reloading, or re-using, just like one will re-use a glass bottle to fill it again with beer or milk. Recycling a glass bottle will mean turning it back on melted glass form, so the new glass is used to make a glass, a bottle, window glass of whatever.