Take the magazine out of the pistol.
Now hold the pistol Upsidedown.
Then retract the toggle all the way to rear and shake the pistol a bit.
At that point release the toggle and see if the toggle is locked to the rear.
If the 'holdopen' is present and not stuck in the down position by rust, old oil, ect,,simple gravity will often let it drop in front of the breech block when the pistol is upside down and lock the pistol open.
Putting the pistol right side up,,the holdopen will then drop back down (disengage) eitherby gravity again,,or preferably by the holdopen return spring pressing on it. Simply pull the toggle back just a bit and let it forward to disengage theholdopen and close the breech.
You should be able to see the holdopen itself in the frame when you pull the toggle all the way open.
It's an L shaped part that sits in a reverse L position. The lower leg of the L is accross the base of the breech block. The longer stem is along the right side of the magazine well.
The 'button' on the side of the Luger magazine is what activates the holdopen.
The holdopen is held down (disengaged) by it's holdopen spring. A lightweight narrow flat spring that sits over the top of the holdopen and engages the holdopen pivot pin to it's rear in the frame.
As the magazine button rises along the side of the magazine as shots are fired and new rounds fed into the pistol, the button climbs higher and higher along the side of the mag till on the last shot fed from the magazine that button engages the holdopen and pushes it upwards against it's flat spring pressure.
That upward movement makes it pop up in front of the breechblock as it travels to the rear and then holds it there, breech open on the last shot.
Sometimes aftermarket magazines don't quite fit right. The button may be too big around to slide freely, or too small around to engage the holdopen. Too thin to engage the holdopen is also a problem sometimes.
Hold open can just plainly be missing, but it should work even if the holdopen spring is not there.
If the spring is there, be careful removeing. It comes out w/o much of any bending to remove. It slips out from under that pin. Much bending to remove it and you'll have a two piece holdopen spring,,not an uncommon thing. Repro's are available .
