Hmmmm...the first link in this thread gets you to a patent app for the Freak system, and the second link gets to you a chrono system but there's no link to any guns like
"http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=2&f=G&l=50&d=PG01&p=1&S1=%28paintball+AND+gardner%29&OS=paintball+AND+gardner&RS=(paintball+AND+gardner)"
or
"http://appft1.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=3&f=G&l=50&d=PG01&p=1&S1=%28paintball+AND+gardner%29&OS=paintball+AND+gardner&RS=(paintball+AND+gardner)"
oh well...the patent app about the Velocimeter talks about optically sensing the velocity, and you'd only need two sensors to do this, unless you use a laser. Actually the radar idea is probably workable and fairly reliable...you're not going to tell me that you can shoot fast enough to outpace a signal that goes about 186,000 miles per second...same for the laser but I think the hard part would be to distinguish which of the string of balls it's measuring...okay so maybe the radar idea is not so hot....hmmm....back to the drawing board.
BTW, there already has been an on-barrel optical chrono, but you have to hang it on an existing barrel. The patent talks about one built into the stock barrel. I tend to think going optical would be cheaper, but a step backwards...but price point is important. I guess if everyone on the field had a built-in radar chrono then someone would come up with a radar jammer that would mess with your opponents gun to make his balls either fall at his feet, or zing by at 500 fps. Hmmmm.....
Ray