CZ-USA CZ712 Semi-Auto Shotgun

[hilltopper55]

I just purchased a new CZ712 Auto Shotgun. The stock is bored for a sling swivel but the forearm is not. I has the screw on cap like a Remington 1100, but the cap will not work on the CZ. I need advise on finding or making a swivel stud base in the factory cap. Looks like enough room for a nut on the inside. I would appreciate any thoughts on my problem. Thanks