GBB: KSC Glock 19 with metal slide
Propellent: at least 6 bottles of Propane
Use: For over a year, thousands and thousands of rounds fired.
Mods: Upgraded spring.
Notes: Pretty hard on my guns, been bumped, dropped, and cleaned infrequently. The only thing I do religiously is put a lot of oil in the top of the propane bottle when I am filling my mags. Have 5 mags that don't leak at all.
IMO: If you are looking for a reliable gun, I don't know of a better one.