What caliber are you looking for?
I use basket weave stamped black leather speed loader pouches made for N frame 357 Mag speedloaders. HKS makes them, also I use the ones sold by
Gall's LawEnforcement Co.(www.galls.com) I can carry two six round 45ACP
moonies in each side. This really a pretty neat set up You just unsnap the flap and stick your index finger in the center hole of the moonclip to pull it out of the pouch and load in the cylinder. Twenty four rounds(six on top of six) in each pouch.Good luck. Galls part number is G4152W
I carried a four inch 625 about a year and a half on duty--never noticed any problems of any kind. Actually a pretty straight-forward way to carry 24 extra rounds.