Yeah, I actually bought that one because you had mentioned that it would fit in the stock tube. It doesn't, but it does fit in the buffer tube so it's no big deal. VFC updated the 416 at some point and my guess is that they went to a more correctly sized stock, which means it wasn't large enough to fit the lipo in the stock tubes. As a comparison, my PTW has an oversized crane stock that will fit sub-c cells, but my old G&G M4's stock was smaller and only fit 2/3A. I'm thinking VFC started with stocks that would fit the larger cells and then switched up for the version 2 416.
[edit] I just double checked. That lipo does fit in my PTW's stock tubes and does not fit in my VFC 416's stock tubes. If you wanted to run it in the stock tube, look for a crane stock that will hold sub-c sized cells.