Sorry, but I don't understand what you are saying! What is a recoil lug "CAP"? Are saying the forward recoil lug is is glued on the barrel? If so that is not true, the block is made of aluminum, and is fitted to the barrel with screws. The through bolt for the action recoil lug is steel, and is a true through bolt! The galssing as a backing for the forward recoil lug is aacra-glass