Hi
I've got an X6-9-L1 on order, and have been researching red dot mounts, too.
Here's what I've learned.
Sig customer service won't tell me what kind of dovetail cut the gun has. "It's proprietary". How's that for service.
Leupold has the Delta Point. It comes with a mounting plate that they say will work. According to them, & Brownells, the cut is a standard p226 dovetail.
I also found a plate for the Burris Fast Fire 2 at Narchez. I can't post the link, but if you do a search, it should show up.
Good luck.
