The RoF bug is an automatic weapon (the Handmade Rifle, for instance) will randomly increase its Rate of Fire by a rather large amount, typically ending up in the 300s. This might sound like a good thing, but when your 90 RoF rifle fires, the sounds and animations are all screwy, not to mention it's very immersion-breaking (at least for me). "Like an automatic radium rifle, the handmade rifle with an automatic receiver will occasionally have a glitched high fire rate; i.e., with the powerful automatic receiver, the fire rate may be 113, or 374. [verified]" This has been a vanilla issue for as long as I can remember and happens across any mod weapons too. I recently experienced this problem with Wasteland Melody's Service Rifle. If you haven't experienced it, then I think you're very lucky, because it annoys me on a regular basis lol.