Colt alteration M1841 rear sight

[dbrad]

Hi all, I recently purchased a Zoli M1841 with rear sight missing. I have decided to convert it into a Colt alteration. I have been able to purchase the repro sight from Lodgewood on a recent trip to the States but I am curious about the small screw that is in the middle of the 100 yard leaf. What is it for?

Thanks,
Damon

 

[Jobe Holiday]

The vertical screw down through the base was to apply tension to the base to keep the sight from moving in the dovetail.
J.

 

[dbrad]

Thanks Jobe, I wondered if that was its function but I wasn't 100% sure.