I have had this thing about 8 years and it\'s still solid. Started off as a M249 MkII and has changed little by little each year. Recently I chopped off the vehicle mount and replaced it with additional rail space. The the gears, and piston were mostly replaced a few years ago. It runs on a Lonex A1 powered by a big 3000 mah 7.4v lipo. Barrel is a 363mm Madbull Black Python 6.03 and a madbull red bucking with a pen tube for a nub. Box mag is photo is an A&K sack mag that runs surprisingly well for $50.