Moisture isn't an issue. If your holster is wet (leather or otherwise), dry it out. Wipe your gun down every evening.
I see you must not sweat much, and/or dont live and carry in a warm, moist environment. Moisture is a very BIG issue for those of us who do. I dont know how you "dry" your holsters out, but they dont dry out overnight by themselves, and most of the time, they dont dry out at all, even when used in rotation, as I used to do. In about 25 years of using leather holsters daily, I never made it through a summer without rust being an issue that required constant attention, and some to the point of having pits polished out and guns refinished every couple of years. Hard chrome and kydex stopped most of that.
I used to go through two to three good, brand name leather holsters each year. Summer was always the hardest on them, and my guns, and once they were wet, they usually stayed wet until the weather broke. On average, it was costing me about $150 a year in holsters. My first Blade Tech was used daily, for over 10 years, and cost me about $50. While it was retired about 10 years ago now, I still have it, and its still as serviceable as the first time I put it on.
This is the Colt Commander that was in it for those 10+ years. It started out as a nice, deep, Colt blue, and lasted almost a year in that finish in a couple of Galco Royal Guards. The first hot summer month, its slide, and along and under the grips, were rusted heavy enough to require the services of a gunsmith to correct it. The finish on the rest of the gun that wasnt rusted, was already getting that washed out look you often see with guns that get a lot of use in leather holsters. At that point, I had it hard chromed and picked up my first Blade Tech IWB. The gun was carried daily and shot (from that holster) weekly for the next 10+ years. The black streaks you see on the gun are actually polished chrome, from contact with the holster. Thats ALL the wear (over 10+ years), and if you look, some small dusting of surface rust around the grips (safety side) where the holster didnt cover the gun. Other than that, the rest of the finish pretty much looks as it did the first day I got it back from being hard chromed.
Same gun and the holster (on right). The holster on left was a new, unused back up.
This is the last Royal Guard I used before switching. Its got about a month of use on it. The tape was a feeble attempt at stopping/slowing the sweat from soaking through the leather. it didnt work.
I know we dont all have the same lifestyle, and our use may be very different, but if you have an active lifestyle, and work, live, and play in a harsh environment, kydex is by far, is the better material if you want your gun (as well as your body) to be protected. Those few streaks of wear on the gun are NOTHING, compared to what it looked like (due to riding in a leather holster) just before it was refinished. I've since carried a number of SIG's, including older, blued guns, pretty much exclusively in Blade Tech holsters, and not a spec of rust, and very little holster wear on any of them.
