Mine fits fine in a owb Blackhawk serpa G17 holster.
I took a closer look and figured out why mine doesn't fit. The tall front sight is the culprit. The Serpa sight groove isn't roomy enough.
Had that problem with the Serpa and a S&W 5903 with target sights. A flat file, a round file, and a little while and the fit was right. But there’s several pressure points the tall sights enhance. Just have to keep filing and checking till it’s like you like it.
Colossians 3:17 (New King James Version) "And whatever you do in word or deed, do all in the name of the Lord Jesus, giving thanks to God the Father through Him."