I haven't changed mine out in five years, not sure how your ammo is getting sticky or corroded?

I suspect it was a function of the tanning chemicals in the leather pouches.

See the post on page 2.

The traditional story about why certain cartridges, especially the 38 S&W Special, were first made with nickel-plated cases was because when carried by police officers in loops or even dump pouches starting in the early 20th century, the chemicals used in tanning back then would corrode bare brass. Not only would that make it difficult to impossible to chamber such rounds, there were even stories of cartridges’ being corroded to the point that they couldn’t even be removed from loop carriers.

Corrosion wasn’t limited to ammo carriers either. I have some old US military leather goods and it’s common for corrosion to form around anything that was made of brass.

Although I’ve never tried to research the issue, I get the impression that more modern leather tanning methods eliminated the corrosion problem, and I’ve never experienced any issues with the articles such as magazine pouches that I have. And of course for anything made of fabric or plastic tanning is completely irrelevant.

The only leather I use around my firearms is Waxed Harness Leather, never had any garbage form on my cartridges or firearms.