Primary Arms PAC5X - Thumb Screw Question

I finally decided to get a PAC5X, but PA is telling me they’re out of the thumb screws. I need one because I’ll be mounting this on a carry handle upper. I hate to wait just for a thumb screw, but my searches of the Internet haven’t uncovered the right size of thumb screw to use as a substitute.

Does anyone know the size and thread count (or thread pitch, if metric) for this item?

Many thanks in advance.

What are you talking about? Are you talking about a carry handle mount?

Correct. According to PA, the base can be removed for use on AR15/M16 carry handles. I plan to put this on an A2 upper, and there’s a thumb screw that goes up through the hole in the carry handle and into the scope. Unfortunately, PA is out of them. That little screw is the only thing keeping me from making my purchase because I don’t want to buy it until I know I can use it.