I bought a bi-pod at cabelas, just a basic one for $20, and superglued a strong magnet to the barrel right by the stock. This seems to work for me the five times Ive done it.

I think that this is better than a homemade one because it telescopes out quickly and easilly and Ive thrown it around and dropped it a few times every times Ive used it.

I know this is sort of a goofy thing to do but I seem to like using it this way.