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After all my years of shooting handguns, you'd think I know the answer to this question.....oh, well

I understand, basically, how locked breech semi-autos work, but once the barrel has unlinked from the slide, what brings the slide forward again to link up with the barrel? It looks like to me that the recoil spring underneath the barrel would just pull the barrel forward, not the slide. Does the slide have another spring that powers it forward again to link up with the barrel?

Also, it looks to me like blow-back operation with a fixed barrel would offer the potential for more reliability and better accuracy. But, does it really offer these advantages in real-world operation?

Thanks in advance for your help.

Crash

The recoil spring acts on the slide to bring it forward into battery. While the slide moves forward, the barrel breach is cammed back upwards and slightly forward to mate properly with the slide.

Blowback operated guns have a potential for greater accuracy IMO due to the fixed barrel, but keep in mind that many of them have a reciprocating slide that carries one or both sights and it can introduce sight to barrel alignment inaccuracies just like most recoil-operated guns exhibit. This sort of inaccuracy is usually not an issue at shorter ranges for most shooters, though. As for reliability, with fewer moving parts a blowback operated gun should be marginally more reliable than a recoil-operated gun (all else being equal). In actual practice not all is equal and recoil operated guns often have a sterling record of reliability. YMMV, of course.

I think that your confusion is the same that I had long ago. When you look at the whole top end while it is off the frame, the cut out in the barrel is what is holding the recoil assembly in place. Once you pop that slide on the frame, there is a "shelf" in the frame that the spring is sitting on and pushing off of, it is no longer being held by the slide/barrel like it is when the slide is removed.

Crash wrote:Also, it looks to me like blow-back operation with a fixed barrel would offer the potential for more reliability and better accuracy. But, does it really offer these advantages in real-world operation?

Strictly speaking, yes (or at least that's my understanding... I am not a gunsmith...). It's not done much with anything stronger than a .380 though, because of how strong the recoil spring has to be to prevent, um, "gas-assisted" early ejections.

Dave2 wrote:

Crash wrote:Also, it looks to me like blow-back operation with a fixed barrel would offer the potential for more reliability and better accuracy. But, does it really offer these advantages in real-world operation?

Strictly speaking, yes (or at least that's my understanding... I am not a gunsmith...). It's not done much with anything stronger than a .380 though, because of how strong the recoil spring has to be to prevent, um, "gas-assisted" early ejections.

Hi Point made blowback operated pistols in .45ACP and down. Uzis and MP40s are blowback, the Pedersen device, used to fire a pistol size cartridge from a 1903 Springfield riflewas blowback, M19 Grenade launchers, Ruger 10/22s, and a variety of others. Just sayin'.

Crash wrote:...but once the barrel has unlinked from the slide, what brings the slide forward again to link up with the barrel? It looks like to me that the recoil spring underneath the barrel would just pull the barrel forward, not the slide.

Don't forget that the front of that spring is set against the slide. That barrel moves back slightly until it locks. The slide keeps going back.

When the slide reaches its travel limit, the spring pushes against the locked barrel and the front of the slide to push the slide forward.

When the slide is almost all the way forward, its momentum carries the (then unlocked) barrel forward and into battery.

Here is an illustration of a striker fired version:
http://www.genitron.com/Basics/Interactive-Glock-Pistol" onclick="window.open(this.href);return false;

This illustration contrasts the difference with a pistol that does not use the tilting barrel locked breech mechanism originally designed by Browing. Note here the recoil spring is placed between the frame and the front of the slide, not the barrel. The barrel never moves.
http://www.genitron.com/Basics/Interact ... tta-Pistol" onclick="window.open(this.href);return false;

Finally, here is a nice illustration of M1911 assembly and operation:

[youtube]http://youtube.com/watch?v=E6SmlOEzNBs[/youtube]