Still not sure, measures almost 5.33mm. But haven't pulled site out. Hoping part number identifies the size from invoice. I want to go allittle tall then file down if need be. If it's a 5.5 then i would almost be better if with 6.5 but if it's the 5.25(leaning towards). The 6 should be good almost right. Used valve lash gaudges, while pistol in a vice with site pic/bore sighter set to target 18 ft away. In garage.
Do have a question. Never sighted like this before is there a distance that will most likely level the top of the sights and barrel(not trajectory).
Thanks