Hey Tuner, xray of 1911 firing

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Easy one, Carl. Bullets are smart, see? They know that if they're fired in a blow-forward pistol that they have to drag the barrel forward to make it work, see? But if they're fired in anything else, they know not to do it. Simple!

I'm surprised that a sharp guy like you didn't figure that out...
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Apply that thinking to what you're arguing for just a second, Tuner. You're claiming that this impressive "bullet pulling" force is what's ACTUALLY "locking" the 1911 during operation, yet the various blow-forward designs (Schwarzlose, Hino-Kinomura, a few others) show that this force is next to nothing; if it WASN'T, you wouldn't be able to COCK them by pulling the barrel forward.
 
SDC

I think that what you and I were doing is thinking of bullet drag down the barrel?
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That's what Tuner is trying to convince me of, but failing :D If something like this mystical "bullet pulling" force has enough energy to do what he CLAIMS it does, we should be able to see some evidence of it in operation, for example the open-bolt 20mm Oerlikon, or when using different bullet/projectile weights.
 
"...it would still operate as a straight blowback..."

If I may jump in, I don't think that there is any question about whether it could function as a straight blow-back action: it probably could, at least for a little while. The point of locking the barrel & slide together is to reduce the speed of the recoiling slide enough to keep the gun from beating itself to pieces and from venting gas through the ejection port. At least, that is my understanding.

--Bill
 
it would still operate as a straight blowback because there is no way that the slide can open as fast as the bullet can clear the barrel.
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This just gets better and better...

It's not necessary for the slide to open very far to blow a case head...which is why delaying breech opening is critical. All it has to do is back away from the barrel far enough to let the case back out about .015-.020 inch while the pressure is still on.

Read that again, and understand that the function of the locking lugs...the ONLY function...is in preventing the slide and barrel from separating before the bullet exits. That occurs horizontally. There is no positive lockup before the gun fires. None.

And it DOES function exactly like a straight blowback. The only difference is that the slide doesn't move independently of the barrel until the barrel links down...after the first 1/10th inch of travel.
 
that's what the LUGS are there for, remember?

No no no! The lugs are there to keep the slide and barrel from separating under pressure. The lugs don't lock the gun when it's static/in-battery. The just mesh together...like gear teeth.
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The slide most certainly IS locked to the barrel when the pistol is in battery, unless you believe that the metal of the barrel can move through the metal of the slide.

Re-read this part...carefully this time.

"The presentation and introduction of a loaded cartridge into the chamber of the barrel-and CLOSING AND LOCKING of the breech-are automatically effected through or by the energy of the recoil of the breech bolt-or that part which AT THE TIME OF THE FIRING OF THE SHOT closes the breech of the barrel."
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And it's clear to me that you're reading something into this description; this simply says that the energy of firing a shot is used to operate the mechanism of the pistol; that's all, and it makes no mention of "bullet pull" to do so.

but it was designed to operate as a "blow-forward" design (the energy of the cartridge firing is directed against both the bullet and the barrel

No. That ain't what it said in the description posted...but I guess that now the people who engineered it don't know how it works any better than Browning understood the 1911.

Here's a cut and paste exerpt of the blowforward description. You may want to go back and take another look.

"The bullet is fired down the bore of the inner movable barrel. The movement of the bullet along the bore of the inner movable barrel drags the barrel forward against the action of the bias spring."
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In the blow-forward design, you have three important parts: a standing breech (which cannot move), a barrel (which can move) and a bullet (which can also move). Since the firing of a cartridge CAN'T move the standing breech, that means it has to move the other two components in the equation, the bullet and the barrel.
 
And it's clear to me that you're reading something into this description;
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Lemme go look at it again...

"The bullet is fired down the bore of the inner movable barrel. The movement of the bullet along the bore of the inner movable barrel drags the barrel forward against the action of the bias spring."

(sic) "The movement of the bullet along the bore...drags the barrel forward."

Not a lotta room for interpretation there...
 
It's not necessary for the slide to open very far to blow a case head...which is why delaying breech opening is critical. All it has to do is back away from the barrel far enough to let the case back out about .015 inch while the pressure is still on.
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If this was going to happen, why don't we SEE it happening with designs that are meant as blowbacks from the get-go? We definitely see it happen when someone gets over-active when they're "throating" a barrel , but that's equivalent to having a hole in the chamber when you fire a round.
 
"why don't we SEE it happening with designs that are meant as blowbacks"

They use lower pressure cartridges?

--Bill
 
Lemme go look at it again...

"The bullet is fired down the bore of the inner movable barrel. The movement of the bullet along the bore of the inner movable barrel drags the barrel forward against the action of the bias spring."
Click to expand...

That's from a description of the blow-forward action, not of the Browning locked-breech action; as I said earlier, if this "bullet-pulling" force was the immense factor it's claimed to be, we wouldn't be able to COCK a blow-forward pistol with our bare hands. Somehow, I don't think a pocket pistol that you'd have lay down and cock with your legs (ala the PIAT) would have made it into production.
 
It's not pressure, but recoil impulse, energy, and momentum that precludes using a straight blowback design for higher-powered rounds. Since the blowback utilizes slide mass and/or recoil spring resistance to delay the breech opening, anything stouter than .380 would make for a top-heavy, clumsy pistol. The High-Point pistol is a good example. The slide is massive.

But...For a mounted or crew-served weapon, the sky is pretty much the limit. It doesn't need to be portable, so the breechblock can be as big as it needs to be...and one could keep adding weight to it until it wouldn't move at all. Then again, you could do the same thing with a locked breech/recoil-operated weapon too.

If this was going to happen, why don't we SEE it happening with designs that are meant as blowbacks from the get-go?
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Well...We do...if we have enough experience to actually understand how they work. All it takes for a blowback to do that is for the owner to neglect changing the recoil spring for a little too long in guns that opt for high spring tension to perform that function in order to keep the slide mass low. These guns have horrendously strong recoil springs for their size and caliber.
 
It's not pressure, but recoil impulse, energy, and momentum that precludes using a straight blowback design for higher-powered rounds. Since the blowback utilizes slide mass and/or recoil spring resistance to delay the breech opening, anything stouter than .380 would make for a top-heavy, clumsy pistol. The High-Point pistol is a good example. The slide is massive.
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Which returns me to the example I posted earlier, of the Hi-Power which has had it's locking-lugs ground off so the pistol works as a blowback; it certainly works, but if the short-recoil system works without battering the slide or frame, why not use it? At the least, it shows that this "bullet-pulling" force isn't required for the pistol to operate.
 
No no no! The lugs are there to keep the slide and barrel from separating under pressure. The lugs don't lock the gun when it's static/in-battery. The just mesh together...like gear teeth.
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Gee whiz, Wally! Last time I had any tilt-barrel-locked slide/barrel combo off of a frame, the two were solidly locked together (in that all-important bore-axis "longitudinal" direction) whenever the barrel was up enough for the locking lugs to engage.

Sounds like some people are getting confused because pulling back on the slide when the thing is put together makes the slide act like the "unlocking" lever, so to speak. Take the slide stop out of your 1911 and tell me how well you can unlock the barrel/slide by pulling back on the slide, eh?

A little math please? a .452 bullet has a bit more than .0160453 square inch area. That means it takes about 6.23 of such circles to equal a square inch. IF it takes about 200 lbs of force to push the bullet down the barrel (educated guess from my limited "slugging" experience), then the "PSI equivalent" is about 1,246 PSI on the bullet base needed to push it through. Assume, with all dangers, a powder-puff load of 12,500 PSI, which *is* enough to obturate any lead bullet, and there's another 12,250 fps at peak pressure being used to overcome the bullet's intertia.
 
Grump...

Take the slide stop out of your 1911 and tell me how well you can unlock the barrel/slide by pulling back on the slide, eh?
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Of course it won't "unlock." The slidestop crosspin is what the link uses to draw the barrel vertically out of engagement with the slide. That's why the crosspin is inserted through the open hole in the link. Now...Let's see if you can tell us why the slide will only travel about a quarter-inch with the slidestop removed. Hmmm?

Don't help him! Let him answer.
 
re:

Time's up, Grump. You may be excused. I suggest that you take some time studying the gun. eh?

Okay...This has been a hoot, but I'm gettin' bored. Time to drop the rest of the story. I'd hoped that, with all the clues, it would have been clear to the ones who cannot see...so I'm gonna go ahead and spell it out. Those that see it need no further explanation, and there's no sense in continuing to say the same things over and over.

The locked breech/recoil operated 1911 is almost...ALMOST...a delayed blowback pistol. The only minor detail that keeps it out of that class is the fact that the slide doesn't move independently of the barrel.

There are six factors that work to delay...resist...the slide's rearward trip to the stop surface.

They are:

Slide mass. The inertial resistance of the slide itself, including all the attached hardware.

The recoil spring. A variable resistance with a dual function.

The barrel's mass. Since the slide has to accelerate it backward, it must overcome the barrel's inertial mass.

The hammer's mass...which includes the attached hardware.

The mainspring's resistance...including the mainspring cap and the inertial mass of the spring.

The forward drag that the bullet exerts on the barrel by virtue of its tight fit and forced passage through the barrel. This force can't be underestimated because it's doubtless the most powerful and resistive of the six. Pushing the bullet through the barrel requires more force than is required to overcome the resistance offered by all the others combined.

This last one is very easy to demonstrate...if the non-believers will simply take the time to experiment with it...and think about it.

Take care all. Study hard. The light will go on eventually.
 
Thanks a bunch for your very correct input Tuner.

It would be nice to share a meal with you sometime.
 
I have read this post from the begining I don't know how many time and keep me attached as the first day. Thank you all the posters for this great lecture.

CZhen
FL
 
how would they function without a recoil spring

I've been reading this thread since the beginning and I was compelled to register, so this is my first post. Hey Tuner, I'm with you and I've got a question that may or may not help prove the bullet pull theory. First of all I don't recommend anyone actually do this unless you have access to the bomb test range that myth busters use:D, but what do you think would happen if a person were to take 2 pistols, 1 blowback operated, and 1 locked breech recoil operated, and fired them with no recoil spring. I would be willing to bet that the blowback pistol's slide would start moving backward almost instantly resulting in a blown case and possibly a blown gun. I would say that the recoil operated locked breech pistol would fire 1 round and the empty case would probably be intact indicating that the breech is being locked by the 2 opposing forces you speak of. If that would be the case then anyone should be able to see that something else is at work other than slide and barrel mass and recoil spring strength. I saw in a post a while back where someone said they successfully fired a 1911 without a recoil spring and it fired 1 round with no adverse affect, can't seem to find it though.
 
The forward drag that the bullet exerts on the barrel by virtue of its tight fit and forced passage through the barrel. This force can't be underestimated because it's doubtless the most powerful and resistive of the six. Pushing the bullet through the barrel requires more force than is required to overcome the resistance offered by all the others combined.
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And do you actually have any EVIDENCE to support this? Going by what we see in blow-forward designs, that "bullet-pulling" force is only enough to compress a recoil spring, and certainly doesn't deliver the thousands of pounds of force that you'd have us believe.
 
Holeshot. The slide in either one would start moving immediately...spring or no spring. The difference is that the locked breech pistol wouldn't allow the slide and barrel to separate until well after the bullet exits. The blowback...as long as the spring is good...is supposed to delay the slide long enough to let the bullet leave...but install a 3/4 power spring and watch the fireworks.

Ned Christiansen fired a 1911 pistol repeatedly without a recoil spring about 5 yeas ago to show that the spring didn't have any effect on unlock timing and barrel drop.

SDC...I'd suggest that you take a course in applied physics at a local community college, but at this point, I don't think you'd believe that either...and if you'd go do the cork and pipe experiment, you'd have all the evidence that you need.
 
SDC...I'd suggest that you take a course in applied physics at a local community college, but at this point, I don't think you'd believe that either...and if you'd go do the cork and pipe experiment, you'd have all the evidence that you need.
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I could do that (to go with my other degrees), but if this is such a self-evident concept, it should be simple to prove, right? Which cork and pipe experiment in particular are you thinking of? I've seen at least half a dozen "cork and pipe" experiments, but don't recall any of them having any relation to what you're claiming. The biggest thing you could do to buttress your claim is explain how it is that this "bullet pulling force" is simultaneously so weak that it can only pull a couple of ounces of barrel against a spring (as in the various blow-forward designs), yet still be so powerful as to exert thousands of pounds of "locking pressure" against the lugs in a short-recoil design. You said yourself "They know that if they're fired in a blow-forward pistol that they have to drag the barrel forward to make it work, see? But if they're fired in anything else, they know not to do it. Simple!"
 
I'm gonna leave ya with one final clue...or actually remind you of something that you seem to be in denial about.

If it CAN affect it...it WILL affect it. You keep trying to ignore an involved force, and a formidable one...but do carry on. Hear?
 
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