First Post, and an Open Ended Question

[Lugerdoc]

Cirelaw, Just to make life interesting, the M29 Swiss and Mauser Parabellum grip screws use a different thread than your standard P08. David, I do have many vg bore used 9x100mm long barrels in stock in the $60 to $75 range + S&H. TH

[cirelaw]

Thank You for the clarification! My name is Eric~

[David-NY]

Originally Posted by alanint

My main question is whether there is a "stop" designed into the interrupted threads? In other words, would anything placed and turned on it stop, or can you continue to turn until you can remove whatever was placed on there?
If there is no "stop" designed into the threads, I very much doubt it was designed for a suppressor.

No stop. The threads were cut, and then someone milled out (or otherwise removed) the 2 "gap" areas. Nothing I can see would prevent you from (for example) attaching an appropriately sized and threaded nut and twisting it down.

[David-NY]

Originally Posted by Edward Tinker

Looking very close you can sometimes tell what manufacturer made it / i.e DWM, Mauser, Kreighoff, while Erfurt and Simson parts are acceptance stamped (not proofed in most cases)

Erfurt. The toggle is marked Erfurt and it matches all other parts except for the barrel and extension. The acceptance stamps are the Erfurt 1908-18 stamps on the FAQ. Now interestingly, there is also an "RC" stamp on the front of the trigger guard, which appears to indicate an Erfurt arsenal rework of some sort. It has a hold-open (which also matches) and a lug.

[ithacaartist]

The interrupted/half threads are the same system the Ithaca Model 37 uses to attach barrels. I think this would work the same way for mounting a suppressor, and the body of the unit would bottom on the flange remaining behind the threads--1/4 twist, and it would be snug.

[David-NY]

I snuck out of the office for a little while yesterday afternoon and put about 20 rounds of Federal 115 gr FMJ through the Luger - no hiccups. Looks like this one works. Quite an interesting recoil experience. New barrel ought to show up about the time I get back from NRA . . .

[alanint]

Originally Posted by ithacaartist

The interrupted/half threads are the same system the Ithaca Model 37 uses to attach barrels. I think this would work the same way for mounting a suppressor, and the body of the unit would bottom on the flange remaining behind the threads--1/4 twist, and it would be snug.

The problem with that is that barrels are then locked down, either via a detent or by the mag tube end cap. This system does not provide near enough torque to safely install a suppressor. Swirling gases and bullet spin will eventually work an improperly torqued down can right off the muzzle.

I'm just not seeing this as a practicable suppressor adaptation, unless it was for Hollywood.

[ithacaartist]

Doug,

You're correct about the barrel lock-down on the Ithaca.

However, here's a story that might mitigate the swirling gasses aspect:

George Rhoads designed a sculpture called the Windamajig. Several examples were fabricated, but an occurrence with the first one, basically the prototype, might shed light on this topic. I wrote most of a description of what it does, but will save the read and direct you to this video of it in action: https://www.youtube.com/watch?v=kok97EfvJbk

The example in this video has mounting plates, but the prototype had a threaded pipe coupling screwed to the main post. No one took particular notice that the thing turned counter-clockwise, that is, until the entire sculpture fell off the post--having unscrewed itself--with people watching!

If swirling gasses can un-screw a suppressor, why not use a left hand thread, or a gun with a barrel rifled the other way?

I think heat and pounding set the stage for looseness. With the '37, it was advised that the keeper ought not to be screwed down very tightly if the barrel was hot, lest one find oneself shooting back over one's shoulder!

[David-NY]

It would be possible for a suppressor to lock into the stub at the top rear of the threading. But I am inclined to agree this was a stateside modification - whether it was for looks only or was actually intended to work I don't know.

[Diver6106]

The suppressor could be quickly put on and taken off with this design. It could have a spring latch on the back that locks down in the smooth parts so it would not back off or a one that catches the front ear to keep it on, or any other design. We need to see what goes on the threads! I think the end of the barrel needs careful examination to see it was machined with the threaded section and not added later, although either way, it could be original.