The guy said it took about a minute and half to fill the tank on the gun with the compressor. no clue what size it is. If it takes 30 minutes to fill that small tank i don't want one. i wouldn't sink a lot in it anyway, the gun is right at 300 and that compressor is the same. i figure after you buy extra belts and maybe an extra mag you'd have 700 in it. the belts looked easy to load in the mag.