Shot a paper target, on a plastic election sign, with them once. Funny thing was the pettern showed on the paper, but did not mark the plastic backing. At about 10 yards, it covered the whole 8x11 paper. I doubt it'd be any worse than hitting something with airsoft. Also, they wouldn't cycle the 10/22 action, so manual cycling. I didn't notice any extra fouling, but I only shot 1 box, so not a very big sample.