Manufactured from solid brass and machined to one nanometer of tolerance our arbors are designed to give the operator the precision that they need to dial in any optic solution that are using. These arbors are designed to work with all of our 30 Carbine bore sighting systems the different calibers that are fitted with these arbors are listed below in the fitment guide. These arbors are designed to work with most of your pistol bore sighting needs which typically requires closed chamber applications. We suggest that you refer to the reference guide for your application with the pistol arbor before making your bore sight purchase. We suggest this as it will prevent any possible interface in the bore sighting process, if you have any questions our customer service team is more than willing to offer assistance.