Ah.. do they make lipo stick batteries? I was able to widen the hole of which the stock I had, it had two holes, the one on top of the other one which can be widened to 3/4" providing space for a 8 cell 9.6v battery. Of the smaller cylinder cell not the larger one which is in like the 1500mAh batteries of whatever from the JG G3 that I have too.
I had originally planned on shaving enough from the inside to fit a small lipo in there, but I didnt know how strong the stock would be after that, so I ended up just using a battery bag on the side of the stock. I had the wiring run through the stock and out through the side of the plastic end piece.
Say, with the rifle you had made where did you put the battery. I read some where someone used another wood kit, I think more like the other wooden G3 on here. They were able to install a custom stick battery in the stock. I've been thinking of doing that get I'm not too sure. I think I'll just have it directed towards the side of the stock.