ATI 410 Magazine 5rd is designed only for use with 2 1/2" Shotgun Shells. *Note- The Omni Hybrid 410 shoutgun only works with 2 1/2" shotgun shells. Some manufacturers 2 1/2" shells are actually longer than 2 1/2" and may not operate in this gun. Please check the length of your shells prior to attempting to fire them. The Omni Hybrid 410 shotgun only fires 410 ga cartridges. Do not attempt to fire other calibers of ammunition through this firearm. Other cartridges such as 45LC or 45-70 will not operate with this firearm and may cause damage to the shotgun and harm to the operator if attempted. Magazine will not function with SAFIR Brand T-14 Upper previously imported by American Tactical.