If a rifle has a bayonet lug? I buy a bayonet. So when I saw that my M712 grip had a slot to mount a shoulder stock, I had no option but to buy one for it. lol I opted for a repro made of the finest Chinese pallet lumber that <$60 could buy on ebay. I knew that it would require some modifications to fit the BB gun but under an hour's worth of fiddling with a Dremel tool and various bits and sanders resulted in a functional shoulder stock. It does not 'lock' in place on the pistol but friction fits more than sufficiently to operate. I found that the magazine is snugly held in place in the leather webbing. Some reshaping of the latch profile with a file was needed to have it unlock easily.