Blow-back design mystery

Discussion in 'Hi-Point Pistols' started by cktvt, Aug 2, 2014.

  1. cktvt

    cktvt Member

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    So we all know that Hipoints have a rather, er, prominent slide. And, as we've all been told since the time we were young aspiring gun enthusiasts (asking Grandpa about his Stallard ;)) blowback pistols need a heavy slide, at least in comparison to locked-breach designs, in order to keep their chambers from opening before pressure drops enough to be safe. And yes, every HP I've seen chambered in a "big-league" caliber that are more commonly associated with locked-breech designs (9mm or bigger) tend to be bulkier, like a Hipoint C9 versus a Beretta 92F. All quite logical.

    But here's where the logic begins to fall apart. A Walther PPK 380 is a blowback design, and so is the Sig P230 380, the Kel-Tec P3AT 380, and the Bersa Thunder 380. All are 380 blowback pistols and all are...sleek, sexy, trim pieces that disappear in a pocket. But the HP 380? Its dimensions are exactly like the 9mm. Hardly a pocket gun. Why is that? This is the one gun that HP could make small and trim but it doesn't. Wassupwidat :confused:
     
    Last edited: Aug 2, 2014
  2. Tyche

    Tyche Member

    Probably patents on the design. The only way around that is to either buy the rights to use those patents, or to redesign around them. And either one of them would be a PITA, and double or triple the price of a HP
     

  3. SWAGA

    SWAGA No longer broke... Lifetime Supporter

    Ok I'm gonna take a stab at answering this.....

    The density of Zamak vs the density of steel
    http://en.m.wikipedia.org/wiki/Zamak

    6.7 grams / cubic cm for Zamak
    8.05 grams/ cubic cm for steel

    Which means the slide should be 20% larger for the same weight.
     
  4. cktvt

    cktvt Member

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    Damn you SWAGA - a good answer like that will put this thread to bed before it even gets started. Couldn't you have said it's a secret agreement between HP and the CIA or some such nonsense? That would have really got the ball rolling but nooooooo, you've gotta just blurt out the truth and ruin my whole day. I hope you're satisfied with yourself mister! Geeez, are you sure the CIA has nothing to do with it? ;)
     
  5. HiPointArmorer

    HiPointArmorer Member

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    You know there are many different types of "blowback" designs right? Delayed, Simple, etc. They are not all small guns.

    [​IMG]

    [​IMG]

    [​IMG]

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    [​IMG]
     
    Last edited: Aug 2, 2014
  6. cktvt

    cktvt Member

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    Last edited: Aug 2, 2014
  7. ajole

    ajole Supporting Member

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    It's funny, this exact discussion has occurred several times in the past, so it's not like SWAGA had to go do some serious fact finding, research and synthesis to generate the answer.:p

    Of course, knowing SWAGA, he'll say he did do all that.:D

    But then, knowing SWAGA...he actually DID do it.:cool:
     
  8. SWAGA

    SWAGA No longer broke... Lifetime Supporter

    I just googled Zamak and steel and took the info from Wikipedia so if you what to call that research.......uh no.....;)
     
  9. undeRGRound

    undeRGRound ROLL wif Da MOLE! Supporting Member

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    I LMAO'ed :D



    Some folks are just a born [email protected] ;)
     
  10. undeRGRound

    undeRGRound ROLL wif Da MOLE! Supporting Member

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    But we can correct Swagzy's Math :D

    It's 16.77% more dense:p
    (steel)


    I'd imagine the real reason, in simplest terms is that HP found it easier to just reduce recoil spring tension and use the same slide for ease of sourcing. No re-design or anything, just a lighter spring (prolly overlooking a minor detail).

    I have thought of streamlining a slide, and adding tungsten rod in another area to make up for it, but I have bigger fishes to fry;)
    Would be an awesome engineering exercise though, making that work. Someone would want to buy it for sure! :D
    But I usually keep those gems like that, unless I build it for someone else.
     
    Last edited: Aug 3, 2014
  11. cktvt

    cktvt Member

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    Reusing the slide from the 9mm makes sense as a cost savings with a lighter spring. I like the idea of redesinging the slide to be the same mass but more compact (higher density). Probably prohibitively expensive but a neat idea.
     
  12. mn_doggie

    mn_doggie Member

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    I was outta town when this discussion first started (at least I'm not restarting it up 2 years later.)

    I own a Ruger LCP which many claim is a direct copy of the Keltec 3AT. Neither are blowback models as are the PPK, Bersa and the Sig you mentioned.

    All of those models weigh in at almost double the weight of the LCP sized pistols (9.4 oz) with the Bersa at 20 oz, PPK being either 20 or 21 oz depending upon slide material and the Sig at 18.5 oz. The Sig, Bersa and PPK all have fixed barrels (that's why it was easy for 007 to use a "silencer").

    From page 11 of the Ruger manual:

    The strong locked breech action of the Ruger LCP utilizes a tilting barrel design in which the barrel and slide are locked together at the moment of firing. After firing, the barrel and slide recoil to the rear a short distance while securely locked together. After this initial movement, the barrel is cammed downward from it's locked position, permitting full recoil of the slide and extraction and ejection of the spent cartridge case.


    Rugers .22 caliber pistol SR22 which has a lot of similarities to the Walther P22 is a blowback design with a fixed barrel.
     
    Last edited: Sep 9, 2014
  13. Moestooge

    Moestooge Member

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    It's not the CIA. Get your facts straight. The zamak slide can be traced to a conspiracy between Elvis (recently retired from stocking shelves under the name of "Bubba Ray" at a Wal-Mart in Alabama) and space aliens.
     
  14. Having a heavier Zamak slide is probably one of the reasons that a Hi Point last so much longer than other Zamak pistols. It is beefy for more than one reason.
     
  15. HiPointArmorer

    HiPointArmorer Member

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    The Walther PP (Polizeipistole, or police pistol) series pistols are blowback-operated semi-automatic pistols, developed by the German arms manufacturer Walther.

    [​IMG]

    The P38 was the first locked-breech pistol to use a double-action/single-action (DA/SA) trigger (the earlier double-action PPK was an unlocked blowback design, but the more powerful 9x19mm Parabellum round used in the P38 mandated a locked breech design).

    This is one reason why the barrels are fixed on Hi Points. The blowback design is heavier, but helps a lot with accuracy, especially on the pistols. Being striker fired, because it would be even heavier if it was hammer fired.