I have an 870 supermag synthetic stock and want to put a swing with swivels on it. I have seen the screw on cap version along with the strap however, I don't like how it "holds" on to the butt stock. I would like to use the swivels that can be screwed into the stock. I have found some at a sporting goods store but the contents worry me. The package says it contains a wood screw that goes into the butt. Would this screw work in a synthetic stock??? Will the threads hold? What are other options??

Thanks.