I'm relatively new to glocks and firearms in general so please forgive my newbieness. I purchased a G17 new and have fired between 350-400 rounds through it so far. This last time I took advantage of the new snowfall to ski out to my favorite practice field and during the course of my practice I clumsily fell and in putting my hand out gave the glock a dose of snow. I was careful to field strip and clean out the snow and figuring there was no harm done finished firing another 50 or so rounds. Upon returning home I made sure to do a thorough cleaning and noticed what looks like some wear that I never saw before on the breech end of the barrel and in the slide. I have attached a photo (a little blurry) can anyone tell me if I should be concerned? Thanks all.