the hmr isn't known to have problems with fouling, so the barrel really shouldn't need cleaned after only 50-100 shots.
I'd say clean it good, a bore snake isn't the best cleaning tool but it makes a good field cleaning tool, but use a good coated rod with some good copper foaming cleaner and run patches through the barrel and then foam it again and patch the barrel again, until it's good and clean and then don't clean it again until the accuracy goes away, which should be a few hundred rounds.