[drmajor]

I plan to put a Red Dot on my GP100 with the B-cubed rail.

what holster will fit?

 

[wwb]

Check Uncle Mike's.....

http://www.uncle-mikes.com/

Might have a hip holster, but more likely only a bandolier-type holster for a scoped gun. I have one for my Super Redhawk .44 Mag.

Other than something like what's offered here, you're looking at a pretty high-dollar custom job.