The Baby had an accident!
 

Well, I took my pride and joy to the range tonight for the first time to break her in. Had a few cycling problems then on the fifth round it happened. The toggle would not retract to pick up the next round. Upon closer inspection I found this.
http://www.georgealarm.com/~dgeorge/breech.JPG
:mad: Well as you can guess it was all over then! I packed it up and took her home. <img border="0" alt="[crying]" title="" src="graemlins/crying.gif" />
As to why this happened I can only guess that the breech block was weak there? I did notice that the primer on the round was very enlarged which means high pressure and I had a old style firing pin in.
Well I pulled out my parts box and found another breechblock that matches Ted's bluing and put it in. Plan on testing it out later this week. I was kicking myself about this, but then again I had this gun done to shoot, not be a safe queen! She WILL live again!

By the way the ammo I was using when the incident occured was Federal Ballisticlean which I have fired before in my byf 41 without incident.

PO8, Before test firing with the new breech block, I'd highly recommend checking the head space and installing a relieved firing pin and new spring. It's also possible that your recoil spring is too weak for the ammo that you are using, and causing coupling link to bend and allowing the BB to bottom out on the frame. Tom H.

Good point on the ammo Tom. On custom guns like this, especially one that has been cut down, the action is tuned to work by the builder. It probably should be standard practice to use only the ammo it was "proofed" with at the time it was assembled. Using anything else is a gamble that it will match the force of the proof ammo. On a shortened grip, the spring and spring guide have 15% to 20% less room to work in and absorb the recoil. Hugh can correct me if I am wrong, but it seems like a safe thing to do.

Hugh puts two recoil springs in them, one inside that other that is reverse wound so they dont bind so there is more recoil resistance than if the spring was just cut down, my baby worked great with 124 gr ammo at 1200 fps, but I have just fired it a couple of magazines. I did notice that it had no more recoil feel to it than a standard Luger. I was very surprised to here about this malady.

Doug,

Sorry to hear this. I fired about a box of ammo thru it while adjusting the front sight and mainsprings for function.

I tested it with handloads consisting of WW brass, WW 124 gr FMC bullets, WW small pistol primers, and 5.5 gr Unique. This is one of my standard handloads for all my 9mm Lugers that gives consistant functioning. It chronographs around 1200fps +- @ 15 feet from the muzzle.

I did not have any malfunctions or feed failures once I got the springs adjusted.

I think that the accident was a combination of things. First I attached a pic of the fired cases. As you can see three of the Federal cases show signs of high pressure. They also have pierced primers, the Geco is fine. I think that this combined with an unrelieved fireing pin and old metal also contributed. Am going to have the new block checked for headspace and try it with Winchester ball. http://www.georgealarm.com/~dgeorge/case.jpg

The breakage was due to a pierced primer. The gas came back through the firing pin hole, drove the firing pin back and broke out the part of the breechblock that retains the firing pin. This is normal with a pierced primer and the reason they went to the fluted firing pin, even though that is not always enough to prevent damage.

The breechblock striking the frame had nothing to do with the damage.

Pierced primers could be due to the firing pin or the primer itself, but in this case it looks like a combination of excess headspace and maybe a weak firing pin spring, probably combined with high pressure.

The flattened primers at the top are classic. The excess headspace allows the primer to back out and spread out under its own internal pressure, then internal pressure in the case pushes the case back over it. Meantime, the primer has tried to back into the firing pin hole and apparently did so, since it blew out and let gas into the breechblock.

It is an article of faith among Luger collectors that the guns are carefully fitted. That includes breechblock and toggle lockup, which controls headspace. Swapping parts, or working on things to smooth up the gun can have nasty consequences, though almost always damage is limited to the gun.

HTH

Jim