grampajack
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I've gotten very interested in blow forward pistols recently, and I was wondering if anyone can explain exactly how the Schwarzlose feeds. Unfortunately, I do not have one to study.
How exactly does the Schwarzlose feeds?
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F-111 John
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Forgotten Weapons has some slow motion video:
Full article at Forgotten Weapons: http://www.forgottenweapons.com/early-automatic-pistols/schwarzlose-1908/
Full article at Forgotten Weapons: http://www.forgottenweapons.com/early-automatic-pistols/schwarzlose-1908/
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lysanderxiii
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The same way any other pistol feeds, except the ramp is moving, not the cartridge . . . .
The reason the recoil is unpleasant is imagine holding on to the slide of a pistol when you shoot it, because that essentially what you are doing.
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Mizar
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The slide-barrel assembly, while moving forward, partially strips a round from the magazine (forward direction), clearing the magazine feed lips and preparing it to feed into the chamber.
Are you sure about that? Look closely at the breechface, marked with "S" and where the round is positioned in the two drawings.
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lysanderxiii
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Patent drawing notwithstanding, have you looked at the barrel/breech area of a Schwarzlose?
If you have, you will have noticed that the patent drawing bears little resemblance to the actual pistol. The barrel has a cut on the bottom (you can see this at 7:05 in the second video), that does not withdraw the next cartridge from the magazine it pulls the nose of the bullet forward slightly, the magazine just pushed the rim of the next cartridge up and in front of the breech face. As the barrel moves backwards, the feed ramp in the chamber area (a shallow cut, similar to the one on the bottom, also visible in the video) gets under the nose of the bullet and with the rim stopped by the breech face, the bullet is forced into the chamber.
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Mizar
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No, sorry, look at the second video from F-111 John's post - the slide "tooth" that grabs the cartridge forward is clearly visible. The way you are describing the feeding simply can't happen.
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grampajack
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Man, thanks, it all makes perfect sense now. I knew from the slomo that the round was somehow pushed forward a little to clear the ramps, but I just couldn't figure out how.
HisSoldier
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Any way you look at it all the energy opposing the acceleration of the bullet is turned into recoil (heat too but that's univerdal). Some handguns have a much shorter cycle time for that which is felt as a harsh snap, the locked breech handguns slow it down and segment it so it feels like less. This system, it seems to me, converts some energy into accelerating the slide forward too, but it's the same cycle period as a blowback. I'm interested in any first hand opinions on this. It may be that the slide hitting it's stop and then coming back adds a second snap to it, back sharply, forward sharply, and back again.
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grampajack
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All firearms have the same recoil characteristics up until the bullet leaves the barrel. A split second after the bullet leaves the barrel, semi autos theoretically shorten the duration of the recoil impulse by unlocking the bolt/slide. To be honest, I'm not sure how much recoil reduction this means in real life. I've never shot a semi auto and said Wow, that feels so much softer than a single shot. I've fired my ARs in single shot mode before, and I can't say there was really any perceptible difference. I've also shot a lot of different shells through break over, pump, and semi auto shotguns, and at the end of the day it pretty much boils down to the shells themselves. Low brass feels good in everything, and high brass feels terrible in everything. To me, the biggest determination in recoil is the weight of the gun and whether it has a muzzle brake, not what kind of action it has.
What makes blow forward different than most semi autos is that the barrel is essentially using the shooter as a launch pad. After the bullet has left the barrel, the remaining pressure forces the case out of the chamber, causing the barrel to start moving forward. But since the barrel has a lot of inertia due to its mass, it's going to try to push the frame backwards.
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Carl N. Brown
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The videos show that blowforward action is painful to shoot in .32 ACP. Makes me wonder how it got past the research&development stage and actually hit the market (to fail). But we did get the word masochism from Europe, too.
The only advantage I see is you get an extra inch or so barrel length and maybe a slight gain in muzzle velocity over a conventional pistol of the same overall length.
The only advantage I see is you get an extra inch or so barrel length and maybe a slight gain in muzzle velocity over a conventional pistol of the same overall length.
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grampajack
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I've heard the pain was due to the shape of the grip. Built a little more ergonomically, it might not be that bad.
HisSoldier
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I rethought my statement about energy being the same, if the mass going forward is far heavier than what the shooter is hanging onto then yes, the same cartridge will give different results. Imagine a 1 lb. bullet and a handle weighing 80 grains, most of the rearward impulse would be at bullet velocities. Ouch!
The energy is the same, but the extent of it going whichever direction changes. This gun with the slide moving forward very fast and the area of handle against the palm would likely result in a harsh recoil, and again, the recoil would be back, then forward as the slide stops moving forward, and then back again when the slide goes into battery.
The energy is the same, but the extent of it going whichever direction changes. This gun with the slide moving forward very fast and the area of handle against the palm would likely result in a harsh recoil, and again, the recoil would be back, then forward as the slide stops moving forward, and then back again when the slide goes into battery.
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grampajack
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I'm not sure if I understand. Bullet weight shouldn't matter, regardless of action, as the bullet leaves the barrel before anything unlocks. This is something all guns have in common, is that the breach stays closed until after the bullet is completely out of the barrel.
My reference to bullet weight was regarding that shotgun. I'm just saying that a shotgun is always going to have harsh recoil because of the nature of the beast. I question whether the recoil was really that much worse, if at all, than a normal shotgun. It may have been just the loads they were using, which I'm assuming were full power buckshot. I heard that shotgun didn't work at all with low brass. Anyone who has ever fired a magnum 12 gauge can attest that they didn't enjoy it, and didn't want to shoot more than one.
The increased recoil in a blow forward comes from the barrel acting like a rocket, with you as the launch pad. So instead of shortening the recoil impulse as you have with a normal semi auto, it would add to it. You would have the initial sharp recoil from the cartridge being fired, then as the gun is moving rearward in its recoil travel, you would have a secondary "shove" as the barrel launches forward. I'm just not sure you would really feel it that much.
In my opinion the unpleasant recoil of the Schwarzlose is a little overrated. It is not a soft shooter but is certainly not painful or unreasonably unpleasant. Unlike the HK P7 variants, which require a little strength to initially push in the front grip strap bar but then is easy to keep in, the Schwarzlose requires constant pressure on the front grip safety bar. I understand this doesn't address the original question but the issue was brought up. I haven't shot mine in a few years but I saw the youtube videos and was expecting something fierce. It doesn't bite.
I own two .32 caliber Schwarzlose pistols and never found the recoil especially heavy or even noticeably different from any other pistol of that caliber and weight. But we are so used to the conventional blowback pistol in the small calibers (e.g., a Browning Model 1910) that it is a bit hard to wrap the mind around the idea of a pistol in which the barrel moves forward and the breech block remains stationary. But a little thought shows that the idea is the same. The gas is generated by the burning powder; the bullet is retarded by its own mass (not friction in the barrel), so it acts to block gas escape to the front. We tend to think that the gas pressure pushes the breech to the rear, but the in fact the pressure acts in all directions, including pushing the barrel forward if it can move that way.
IMHO, I think Schwarzlose was the type who keeps saying "what if?" and had enough time and money to try it. Of course, he also had the advantage of not having to compete directly with other designers of pocket pistols who almost all used the blowback system. I found that the Schwarzlose guns are quite delicate with small parts that wear and reduce the gun to an elaborate paper weight very quickly. And of course, today, no parts are available and no gunsmiths can work on them, so I have shot mine very few times, mostly just to say I have done so.
There is another chapter to the Schwarzlose story, sort of. Here is a summary. Prior to WWI, Davis-Warner was the importer of the Schwarzlose pistols. With the advent of war, importation became impossible, so the company had a pistol designed and made for them that looked enough like the Schwarzlose that it could pass in ads and be a "temporary" U.S. market substitute for the Austrian pistol, which, in the event, was never made after the war. Regardless of the advantages, real or supposed of the Austrian gun, the American-made substitute (a normal blowback) was not well made and was positively dangerous due to a major design defect - if the breechblock was not locked to the recoil rods properly, it could come back in the shooter's face, one problem the Schwarzlose absolutely, positively did not have. With what had to be a great example of sheer gall, Davis-Warner named its dangerous, poorly-made and unreliable pistol - what else - "The Infallible."
Jim.
IMHO, I think Schwarzlose was the type who keeps saying "what if?" and had enough time and money to try it. Of course, he also had the advantage of not having to compete directly with other designers of pocket pistols who almost all used the blowback system. I found that the Schwarzlose guns are quite delicate with small parts that wear and reduce the gun to an elaborate paper weight very quickly. And of course, today, no parts are available and no gunsmiths can work on them, so I have shot mine very few times, mostly just to say I have done so.
There is another chapter to the Schwarzlose story, sort of. Here is a summary. Prior to WWI, Davis-Warner was the importer of the Schwarzlose pistols. With the advent of war, importation became impossible, so the company had a pistol designed and made for them that looked enough like the Schwarzlose that it could pass in ads and be a "temporary" U.S. market substitute for the Austrian pistol, which, in the event, was never made after the war. Regardless of the advantages, real or supposed of the Austrian gun, the American-made substitute (a normal blowback) was not well made and was positively dangerous due to a major design defect - if the breechblock was not locked to the recoil rods properly, it could come back in the shooter's face, one problem the Schwarzlose absolutely, positively did not have. With what had to be a great example of sheer gall, Davis-Warner named its dangerous, poorly-made and unreliable pistol - what else - "The Infallible."
Jim.
tark
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Can't really say I have either, But to do this properly you must have an autoloader that can turn off the gas system. I have fired M-14s and M-1As with the gas system turned off, and then on. Can't really say the former had any more recoil than the latter.
What I can't understand is how this pistol works AT ALL! What moves the barrel forward? Is it the friction between the bullet and the barrel pulling the latter forward? Magic elves? The power of the Force? I gotta think the bullet has to leave the barrel before much of anything can happen. Then you are left with the high pressure gasses exiting the bore, in a forward direction, which would push rearward on the gun. What moves the slide??
Something does, as the gun exists and it works. I gotta do some research.
tark
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Found a little info. First, I called the barrel a slide. Gun doesn't have a slide. And it appears that the bullet friction in the barrel has a lot to do with it. What a weird gun! Now I want one! Looks like it's gonna take four figures to do it. 
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grampajack
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It's really simple. First of all, you have to understand that the barrel doesn't move until long after the bullet has left the barrel (relatively speaking), so the pressure has dropped considerably before anything starts moving, which is how all semi autos keep from blowing up. I'm just taking a wild guess here, but I would imagine that the pressure in the barrel is probably less than a thousand psi when the thing actually opens. Who know, may be a lot more, but the point is that by the time the works start moving there's not much high pressure gas exiting the muzzle to push it rearwards at that point.
As for what causes the barrel to move forward, it's just the pressure inside the barrel pushing the empty case out of the chamber. But instead of pushing a bolt backwards, it pushes the barrel forwards. It works just like direct blowback, but in reverse. Just think of the barrel as basically a rocket. Or think of the empty case as acting like a piston.
RecoilRob
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Actually....if anything acts like a piston it would be the bullet itself. Granted there must be some amount of force to engrave the rifling and friction as the bullet is pushed down the barrel....both of which will impart some forward thrust to the barrel. While the powder is burning and the bullet is within the barrel that pressure pushing the bullet also by friction will be pushing the barrel forward. The blowback type action normally does start to have slide movement while the bullet is still in the barrel...but not enough to allow the case to withdraw past the thick web where it's strong enough to withstand being blown out. Without this movement imparting inertia the slide would likely not be able to complete the action cycle.
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grampajack
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If there's any movement at all, it's very slight. Like a few millimeters at most. I've never seen any gun that even started to unlock before the bullet was out of the barrel.
While the bullet does exert some forward pressure on the barrel, it's not enough to overcome its inertia. Which is good, because if it did it would cause the gun to unlock before it was safe. The time interval of the force applied to the barrel is just so short. Imagine you've got a barrel mounted in a pipe in a vise so that it can move freely inside the pipe. Now imagine you're pushing a bullet down the barrel with a ramrod. Obviously, the barrel is going to move instead of the bullet. But now imagine you hit the ramrod with a heavy mallet. The bullet is going to move because you overcame the static friction (think back to the brick, rubber band, and sandpaper experiment from freshman physics). So you can imagine how this works when you accelerate the bullet from 0 to 1k fps almost instantaneously.
It works just like direct blowback. It is direct blowback. Think about it this way. The barrel and the breach want to move apart due to the pressure being placed on the breach by the empty case. It doesn't matter which one moves and which is stationary. Actually, both could move. The bottom line is that pressure is trying to push them apart, and if there's nothing to keep them locked into place, or that mechanism is removed or overcome (i.e. delayed and gas operated), then they will move apart.
I would never have thought of a blow forward mechanism because the things are not intuitively obvious. It just does not make sense, and yet, it works.
Sort of like calculus. The idea of the infinitely small never made any sense to me. In fact, the Jesuits had infinitesimals declared heretical because the whole concept did not make sense to them either. How a Dangerous Mathematical Theory Shaped the Modern World http://www.ams.org/journals/notices/201605/rnoti-p571.pdf
Blow forwards work and so does integration. I would never have come up with either.
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grampajack
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What I'm not getting is how the cartridge is held in place once it clears the feed lips. Let's say you held the gun upside down while shooting it. Would it just fall out?
Mizar
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The cartridge just sits on top of the magazine - no upside down shooting, sorry!
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grampajack
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You couldn't even shoot it holding it sideways. I guess no shooting under vehicles either.
Mizar
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Yep, not to mention that the slide is not red dot compatible and has no rail...
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