I went to the range today with my ruger 22/45. I put about 150 rounds of bulk (blue box) federal 22lr ammo thru the gun, when all the sudden the ammo started to shoot very smokey. Three of the ten rounds in the mag caused a wispy white smokey, and the report from the rounds sounded a little different, quieter and less crisp. My first thought was that the rounds were bad, half-duds or something. So I loaded up another mag. A full five rounds in this mag did the same thing. My next thought was that the rounds were wet, or had bad powder. They all still seemed to shoot ok, but it was disconcerting, so I cut the session short. Has anyone experienced this before, with rimfire ammo or otherwise? Bought the ammo about a month ago, and there is no visible damage to the box or ammo in it. Unfortunately I didn't keep any of the spent cases, otherwise I might look inside for unburnt powder or something. I'm just gonna get rid of it, cuz I'd hate to have a round get stuck in the pipe or something, but I was wondering if anyone else had seen this. Thanks.