Never had a revolver fail to fire because it was dirty from powder, though I never fired more than 100, maybe 150 rounds at a time. As far as auto loaders, I've fired as many as 500 rounds loaded with Bulls Eye between cleanings. Probably didn't need to then, but after a few trips to the range, curiosity finally got the best of me and I finally got around to cleaning it. Most of my shooting is limited to 50 rounds at a time now and I take an hour or longer to shoot that. Not because range time is by the hour, but I concentrate more on each shot rather than slinging lead downrange like i did in my younger days.