Bad consistency

[Maverick99]

My micro mag has to have the worst consitency in the world. I goto chrono it n the fps readings are.....250,225,170,137, and so on. I cant get my velocity up any higher than 250 either or else my gun will start to vent out of the back. I dont even fire fast it is just shot for shot when i chrono. I know its not my nitro tank cuz i can shoot about 10bps on my friends imp with no problem n my cocker works fine wit it. I run a staright macro to the valve from my tank too. Any suggestions on how to fix this problem would be great.

[PyRo]

Make sure there are no obstructions in the line. Be sure your paint-barrel match isn't rediculously big/small. Then I would try changeing the reg seat. If that doesn't work, its probably your reg piston, or possibly the spring.