I have worn out at least two, and more likely three or four, issued handguns during the last 29 years. At no time was barrel wear ever a problem. For practical purposes I had unlimited ammo. I've had alloy frames break and stretch, as well as the guts wear out, but never a barrel on a handgun. I honestly do not think you have a concern. Avoid stainless steel bore brushes and your guns will live long enough to be part of your estate.