Originally Posted by marsoncoleman
which is better and why? i can't find it out anywhere,,,,
You were not trying very hard enough, if trying at all.
Your question has been asked before, many times before, and a specific thread was created to clarify on the matter. More on that in a second. Simply put they are two different guns, quality and model wise. Mach1 also has the exact same G&G M16 for $319 that buy airsoft has as well.
When it comes to G&G there are many varying levels of quality out there.
Please see here for a better understanding of those levels of quality.