I've been running leather OWB 'pancake' style, pistol specific, molded holsters for years, on all different types/finishes of handguns. Some had thicker (baseball mitt type) leather, and some more supple leather (like on a loafer shoe). However, all of them were 'quality' leather holsters. Never had any issues with any of them. I do apply some degree of preventative maintenance measures, though. Like wiping down my pistol every so often with G96 (or equivalent), and also spraying a light coat of G96 inside the holster. Works for me.....
'Thick(er)' Leather
'Thinner' Leather
'Thick(er)' Leather

'Thinner' Leather
