The Delta Series AR-10 Bore Guide will help protect the bore and action of your rifle by properly aligning the cleaning rid and reducing solvent overflow. Cleaning without a bore guide can allow the rod to bow and rub or gouge chamber and throat of the bore causing real damage and loss of accuracy. Keeping the rod properly aligned not only protects your barrel, it directs the force exerted on the cleaning rod handle allowing tight patches to be pushed more easily.