I have this gun, and i have none of the problems you say above; the battery DOES fit in the upper reciever EASILY. As a result the cocking handle DOES move smoothly with a nice metallic CLANG as it closes. I have used many ak's and other airsoft guns, and i would say that this is probably the best chinese clone i have EVER used (within 5 mins of first playing with it, i had annihilated 5 of the enemy team, my teammates refusing to respawn because they were too busy enjoying watching me tagging them).
The grips are nylon, the real deal, and it makes a big difference to the ABS you find on nor