Well if thats the case, Maybe that would explains some of the take down levers I have observed with only a hole where the round button is.
As I recall someone speculated that it was a modification done by personnel in the colder climates in order to make the take down easier operate.
Iâ??ll have to look for the thread, I know it was discussed here.
Here is the link where is was discussed before, but the pics are missing:
Hole