Well I bought the Volquartsen rail, and the factory hardware does not work and using a temp installation the slide sticks.... The slide is smooth with factory back strap. BTW it is a new URX Standard.... Browning screw heads diameter are too big and the counter sink too shallow. The screws that go into the Volquartsen rail are smaller head and countersink is different, steeper angle... THE SLIDE STICKS... I put the factory back strap on, smooth. I suspect the channel the trigger block rides in was not milled deep enough or they put too much finish on it. I spend $50 I don't want to have to sand on the rail.... QUESTION: Where do I buy hardware, and any idea where I need to Mod the rail to make it slide nice, like the factory blackstrap.