Totally normal, and just so you are aware it's not the firearm itself, but the casings of the ammunition and the design of the follower. Handgun casings are headspaced in the chamber off the cartridge lip/mouth. It's hard to explain, and a pic is worth a thousand words so here are two pics, the first is a very detailed drawing of a .45acp cartridge in a chamber. You can notice the cartridge has an extremely sharp mouth that is being used to actually determine the headspace. The second picture is a higher level picture showing a general handgun cartridge and how headspace is measured. Because of this you have a sharp lip on the case scraping against a plastic follower that is ramped to angle the cartridge for feeding. As such the sharp metal lip scrapes the plastic follower smooth until all raised areas are removed (sort of like having your follower hand planed in wood working terms). There is nothing wrong with this unless you are shooting with reloads that are of poor quality and are chewing your followers up.
Nothing to do with the gun. Totally dependent on cartridge follower interaction.