Q&A #17: Bullpups, Stocked Pistols, Delayed Blowback, and More!


0:26 – Can roller delayed blowback system be relevant in modern guns?
3:32 – Difference between gas tappet and short stroke gas piston
6:00 – Cleaning procedure, particularly for corrosive ammunition
7:32 – Brief synopsis of Yugoslavian post-WWII Mausers
10:45 – Final weight of WWSD carbine
11:44 – What hindered automatic arms development during WWI?
16:55 – Why not use MLOK/Keymod for optics?
18:05 – Forward-acting gas pistons?
19:26 – My opinion on the Remington bankruptcy
22:18 – Will 3D printing allow squeeze-bore rifles?
25:39 – What was the last US cavalry carbine?
26:20 – When the the Potato Digger leave US service?
28:11 – What was the first gun I bought specifically as a collectible?
28:55 – Is the FAMAS the best bullpup ever?
33:59 – What nation is underappreciated in small arms design history?
36:28 – Stocked pistols and modern arm brace pistols
41:04 – Do I approach museums and collectors or do they approach me?
42:46 – What is the Segway of modern guns?
44:40 – Are British DP (Drill Purpose) guns safe to shoot?
48:30 – What is the process to buy a machine gun in the US?
54:32 – Soviet TKB-59 triple barreled prototype
57:11 – Would modern high speed cameras have helped gun designers of the past?
58:48 – Why did primer-actuated systems never catch on?
1:01:44 – Progress on MAS-38 SMG and 7.65 French Long ammo
1:04:17 – What are the missing US designations, like rifles M2 through M13?

As always, questions came from Patrons at the $2/month level and above. Thanks to all of you for the support!


  1. Roller and lever delay systems seem waiting for cost reducing improved manufacturing methods both at mechanism building and chamber fluting applications. They will never go off.

    Gas tappet seems a funny application of short stroke piston without gas exhaust and bigger rod mass. The affected reciprocing delocking elements return the so called saved mass however. Besides, the cause for its existence should be questionable IMHO.

    • “lever delay systems”
      These systems seems to work reasonable well with uniform ammunition, however seems to do not like change in ammunition – I am not sure if FAMAS would consume properly all NATO-compliant 5,56×45 cartridges?

  2. The forward acting gas pistons have been utter failures for the most part unless we think about the Kawamura rifle from Nippon Special Steel. In context, the Kawamura design actually makes sense as it allows for a less massive operating rod acting in tension which trips a toggle bolt into opening up. And we presume nobody is stupid enough to stick the muzzle of a self-loading rifle into the mud. I could be wrong…

      • Thanks for the cautionary tale! Too many people nowadays seem to think gun=bang, bang, bang, all day and every day. “Clean my guns? Cleaning is for janitors! Guns are supposed to shoot and kill, not sit around waiting for some dainty maid’s feather duster!” And guess what happened when the idiot tried to fire his prized “invincible” AK after falling muzzle first into thick mud?

  3. “Would modern high speed cameras have helped gun designers of the past?”
    V.A.Degtyaryov used slow-motion in his work at least once: in his memoirs (Дегтярев В. Моя жизнь) he stated that it helped figure trajectory of spent cases which make designing of bag (brass-catcher) for DA (aviation machine gun) easier.

  4. “Why did primer-actuated systems never catch on?”
    Стрелково-пушечное вооружение самолетов (1941) does describe one primer-actuated system and say it was used in automatic Roth gun, cross-section shows that it used special cartridge – more or less its bottom part was “elongated” to allow primer to move along cartridge axis (like piston in diesel engine).
    Author notes that such cartridge is more complicated to produce and also claim that it usage results in early opening [of breech] so extraction of case is hampered and this rules out combat weapon based on that principle.

  5. The smoking jacket is a nice touch Ian. Next Q&A just add the brandy snifter and pipe to complete the ensemble! Scotch will do in a pinch….

  6. “Will 3D printing allow squeeze-bore rifles”
    First question: what would taper-bore give?
    It was introduced in inter-war period and used during 2nd World War most notably by Germans in anti-tank role (2,8-cm-schwere Panzerbüchse 41, 4,2-cm-leichte PaK 41, 7,5-cm-PaK 41) and to lesser extent British (Littlejohn adoptor) which used projectiles requiring possible high impact velocity to work (bigger velocity = better penetration) with invention and spreading of HEAT shells impact velocity is no longer so crucial (HEAT penetration is independent from impact velocity)

    • Squeeze-bore weapons ultimately became a military dead-end, if only because replacing worn out barrels got a bit expensive.

      HEAT shells offered the best armor-penetration capability for lower velocity artillery, especially short barreled large caliber tank guns. The main 7.5 cm gun from the Panzer IV variants C through F-1 (F-2 had a much longer gun barrel) had limited anti-tank capability at long range (as the short barreled gun was intended to attack infantry and pillboxes, not other tanks) as the gun’s relatively low muzzle velocity required more elevation. The same is true for the StuG III until variant F came around. In both cases, the best shell for standing up to other tanks at long range was the hollow charge shell…

  7. “The *solution* to corrosive ammunition cleaning…” Ha! I saw what you did there…

    Yep: water. The “universal solvent.” Water plus ballistol is good for my blackpowder guns and my corrosive milsurp ammo both. Plain water, preferably heated, is great too. The British Home Guard manual basically has the numbers of pints of hot water poured into the bore, followed by dry patching, followed by a single oiled patch. Won’t do much to remove jacket fouling from copper, tombac, etc. but removes the carbon and the ‘salts’ from the corrosive primers.

    Does anyone know the recipe the Russians and Soviets used on the flax oakum/hemp fibers that were used as disposable bore brushes/scrubbers for the Mosin-Nagant? I ask, because it apparently used some amount of lye, which is commonly found in old-timey soaps, but I frankly don’t know the, ahem, “solution.”

    I do believe the French at some point used gasoline as a solvent and motor oil as a lube! Efficient, if somewhat dangerous.

    Segue or Segway of modern guns?? If the the latter, the Kris Vector.

  8. Another awesome episode Ian!! PLEASE PLEASE PLEASE keep us informed of the deal with starline, it will be great to use my dies to make some ammo for my 35A and 35S with some more reliable brass than my converted 32 S&W brass, and then I can keep my 32 S&W brass for my 32 S&W revolvers.

  9. Load-X in Santa Rosa has quite a few loadings in hard to find calibers.
    I’ve been using their ammo for decades and I’ve been happy with it.
    (707) 579-0990.

  10. Regarding Remington’s attempt at re-introducing the 51, I had the thought perhaps part of the problem could be the chambering. The originals were in .32acp and .380acp, and the scaled-up 53 was in .45acp, all rounds with moderate chamber pressure, while the re-introdution model is the higher-pressure 9mm. Makes me wonder if there is something inherent to the Pedersen mechanism that makes it unsuitable above a certain chamber pressure.

      • Also IMHO introduction of new and apparently not tested enough automatic pistol would be slap right into John D. Pedersen face if he would be alive, considering that he make sure his designs worked as intended.

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