M-1 Garand Trigger Housing Group

[EGA1957]

I don't of a better place to ask this question, but I'm not sure where in this Forum where else to ask it.

That is, my M-1's trigger housing has a front/rear "ring" with the front "ring" being the trigger lock.

What was the purpose of the rear ring?

I've seen that ring used for the Korean-era "Winter trigger," but that was era-specific and apparently short-lived. I've also seen that ring used for inserting a round or other object to enable field stripping. But what was it's original purpose?

Did the two different trigger housing unit designs affect the stock's standard opening?

Also, any idea when the change occurred?

[hbharrison]

Putting the bullet in there to help field strip the rifle was the reason it is there lookedat the field guide for the MI-Garand and that is what it said it was for not other reason givin. Same thing on the M14.