Upgrade your AEG for maximum performance with this Tight Bore Inner Barrel from SHS. Constructed fully from steel, this inner barrel replacement can withstand a lifetime of heavy use. The 6.03mm inner diameter ensures the BB will fly straight through the barrel without bouncing around within. This inner barrel is designed to be used in M1A1, MI733, and MC51 airsoft rifles. Stock up on everything you need to maximize your rifles full potential and add this Tight Bore Inner Barrel from SHS to your lowdown today.