Swapped out dots between 2 320's I have, one a XFive Legion the other an M17 Pro cut slide. Both optics are Romoe 1 Pro's. The M17 has this extra cut and spring loaded arm at the breech face and front cut area. Anyone know the part name for the spring or where I can find one? I'll be reaching out to sig tomorrow as well but didn't know if anyone has run into this before.