Barrett MRAD ELR Barrel Maker Kit, 375 EnABELR, Includes Barrel Extension, Barrel Extension Jam Nut, Bolt, Ejector Roll Pin, Ejector Spring, Ejector, Extractor, Instruction Card 19436 MRAD ELR Barrel Maker Kits are available for end users to enlist a competent gunsmith to create a custom barrel for their MRAD ELR in the desired caliber" barrel length" twist rate and suppressor/muzzle brake thread pitch.