This one's been hanging around for a while, but it's pretty obvious that it should be rare. I do find a fair few examples of
rifler online, almost all relating to "egames". E.g. a Reuters item from 6 July:
The six-month run of Pawel “reatz” Janczak as rifler for AGO’s Counter-Strike: Global Offensive team has come to an end after his contract was not renewed.
This specialized usage does not warrant common status.
Rifler will be treated as rare in future.