Shipping costs are based on an estimate of UPS ground or equivalent carrier within the contiguous US, excluding Alaska and Hawaii. Please see Seller's website for actual shipping costs.
M4-type barrel extension has a self-lubricating EXO-treated Nickel Boron finish that aids in smooth, consistent feeding and helps prevent hang-ups. High-tech coating lasts the life of the weapon, and won't rub off, flake off, or gall. Helps dissipate heat for cooler operation, too. Precision machined from 8620 steel to USGI specifications with integral M4-type feed ramps and predrilled locator pin hole. Mfg: Failzero SPECS: 8620 carbon steel, EXO-treated Nickel Boron finish. .998" O.D., 1.168" shoulder O.D. .8125"-16UNF thread. Barrel locator pin required, available separately.