Actually, it is VERY likely to happen, and it DID happen very often "back in the day".
The reason you can't easily find articles on it is because the day of the revolver was "pre-internet", back when you had to subscribe to one of the law enforcement trade magazines for that kind of info. For example, the NYPD started publishing annual shooting incident reports back in 1982, started issuing semiautos in 1992, but the earliest available shooting incident report on the web is 1997.
Since you're looking for articles, you can see from the NYPD report (pic of 2011 table attached below) that about 20% of all NYPD shooting incidents are actually ND's. That statistic has been relatively consistent since the reports started being published in 1982. Since 1992, they've been carrying semi-autos with 12 pound triggers, not much different than a revolver.
The only one that I'm aware of that managed to kill himself with an ND was Frank Golden in 1947. Most likely he was using a revolver at the time.
http://nypd.police-memorial.com/list-of-nypd-fallen-heroes/
You can find the reports that are available on the web here:
http://guides.lib.jjay.cuny.edu/NYPDStatistics
Some of the earlier reports (no shooting statistics) are pretty funny. For example, in the 1921 report on page 99 it shows that there were 57 complaints investigated against fortunetellers, and 40 of those were unfounded. Does that mean that 40 out of 57 fortunetellers are telling you the truth about your future?