Centurion Arms' new bolt design will make your AR platform more reliable and last longer with a lifetime guarantee against bolt breakage. These new bolt has a body profile that creates a larger radius between the bolt lugs and the body that allows the pressure to be spread over a larger area reducing stress points which leads to lug failures. Centurion has also added dual ejectors that help rotate the brass off the bolt face faster to ensures more reliable ejection in rifles while running suppressed or going back and forth between suppressed/unsuppressed. This also helps with platforms that are considered to be “over-gassed”.
E4 bolts include a taper lug design creating more strength in the lugs.
E4 Bolts will require Centurion Arms “T” marked barrel extensions or the Knights Armament E3 extensions to accommodate the taper lug design.
E4 bolts use standard gas rings for logistical commonality and also use standard extractors with black inserts and either Colt OEM extractor springs or Centurion upgraded 5 coil chrome silica stress relieved spring for ultimate reliability (EXT-SPRING) .
Currently Compatible T-Marked Centurion Arms Barrels*:
2024 Batch of 14.5" Hammer Forged Carbine Socom Barrels
2024 Batch of 11.5" Hammer Forged Carbine FBI Barrels
*Previously purchased barrels from earlier batches will NOT have taper lug extensions. You must check your barrel prior to use with E4/ETB bolts.