The adapter worked flawlessly. The machining, fit and finish, along with design are near perfect. One suggestion I would make to Haha to further improve the product would be to include a stop block to fit inside the 1913 rail. This is a minor issue but would help increase strength of the connection to the receiver. On a side note, I think it'd be wise to include a disclaimer along with the product about the importance of using a high quality drill bit and drilling out the Zukrov stock's riveted pivot pin. A cheap drill bit has the propensity to snap and endanger the user. It would be best if the adapter came with such a quality bit but understandably keeping costs down, a simple disclosure or warning would work well.