Welcome to the forum, hopefully someone who has experience of both calibres will come along in a bit. I've only ever owned and shot .177 pistols as in my opinion the lower power limit makes .22s very loopy, even at moderate ranges. However, if you are only likely to be shooting at 10m there should be no problem at all with either calibre and I suspect little or nothing to choose between them for accuracy. .177 are cheaper to run if that matters to you and are the calibre of choice for serious target shooters. Hope this is of some help!