I have a Remington 870 and I just received my Spec Ops Adjustable Stock with a aftermarket forend. I put the forend on myself now things don't seem to work like they use to. If I tighten the nut to the magazine tube (connects the sling) the shotgun will not re-cock. If I losen the nut a little it'll cock just fine. What could be causing this and at all possible can it be dangerous.