Also, this effect appears to worsen when using iron sights in first person mode...
*Update* I tested it again and it doesn't matter whether you're in first or third person, the irregular rate of fire exists in both modes. It also exists whether you are zooming with iron sights or not.
*Update 2* SOLVED. I found a way to correct the irregular rate of fire in the GECK. I'll post a link to the mod I'm making when I'm done.
*Update 3* Here is my new mod fixing the RoF problem:
http://www.gamesas.com/index.php?/topic/1163793-relz-syclonixs-slicker-shooting-mechanics/