oiling my gbb
 

I have a tokyo marui m9 and i need to oil it up a little bit but where should i put oil ,where shouldnt i and what quantity?

Blowback chamber internals, rails, and inside of the mag. Not too much.

Just enough to make things slide smoothly. If it's oozing out, there's too much. If you can feel resistance from a "dry" spot, there's too little.