As long as he doesn't shoot anyone within 100ft, things are no different than a 400fps AEG shooting 0.25g BBs at 40ft which no one ever seems to have any problems with.
Dan, if you haven't already, register on the forum at
www.airsoftretreat.com and go search VSR in the Sniper's Perch. It's an American site, and by far the most useflu of websites for upgrading various airsoft sniper rifles, and the VSR seems to be one of the more popular ones to discuss and upgrade.