39-2 question

[WLB]

I recently purchased a 39-2 and after complete disassembly I have noticed that the hole in the bottom of the back strap insert which receives the main spring plunger is not a complete through hole but rather has a half moon shape to it so it is half a hole so to speak. The tit on the main spring plunger which holds the insert pin just barely protrudes through in the pin hole however it does seem to secure the pin. Is this the way it is designed or do I need to open the hole completely?
Thanks in advance for insight into this question.

 

[armorer951]

The hole for the "grip pin" and the hole for the mainspring plunger are slightly offset in the insert, so the cavities don't line up. This is the way they are designed. The grip pin should be held tightly enough by the protrusion at the bottom of the mainspring plunger to keep it from drifting.

If there is sufficient wear that you need a new plunger, I would suggest purchasing the plastic ones as a replacement. They are less likely to bind on the mainspring, when it is compressed during cycling.

 

[WLB]

Got it.
Thanks for sharing your knowledge.