Now, I searched around for a bit and didn't find any threads on this so here we go. I didn't know exactly where to post this, so mods feel free to move wherever or just yell "Repost!" and put in the appropriate link.
I've seen a few "what mechbox does my gun use?" questions, and I know a few people have probably thought "I wonder what guns use a (insert version) mechbox?" I stole and modified this list from AirsoftRepair.com, and hopefully we can fill it in and flesh it out.
Version 1 Mechbox: FA-MAS Series, L85 (V1 hybrid)
Version 2 Mechbox: Armalite Series (M4, M16, etc.), Some SR25s ("extended" V2) , G3 series, MP5 series except for MP5K
Version 3 Mechbox: G36 series, SIG series, AK series, AUG series, UMP, MP5K and MP5K-PDW, MP40
Version 4 Mechbox: PSG-1
Version 5 Mechbox: UZI
Version 6 Mechbox: M1A1, P90, P90 TR
Version 7 Mechbox: M14
Version 8 Mexhbox: TM Type 89
Most M249s use their own mechbox. (Ver 249?
Any input will be edited into the original post. Thanks for the help and/or "REPOST!" and link.
Also, I didn't know ver.4 and 5 existed. Learn something new every day....