I recently purchase a dry fire device from Brownell's. It slips into the bolt carrier to actas a cusion and allow dry firing of my AR15. Problem: the AR will not close with the device installed. I have contacted Brownell's, who have no idea on how it tis to be installed and and Sinclair Marketing, who sells the device. I have not heard back from sinclair yet. My AR is a new Colt Match Target HBAR. Would this make a difference? I have instleed the device in a full 360 degree with no success. Any Suggestions? Thanks in advance.