The E2 bolt design improves function and offers extended lifespan. Dual ejectors provide significantly increased ejection force, ensuring that the cartridge is cleanly ejected from the ejection port, even when using high back pressure muzzle devices and collapsible stock systems, and provides a layer of redundancy in the event of failure. The bolt lug design has been optimized and stress-relieved, extending overall lifespan to not less than 10,000 rounds. The E2 bolt is completely backward compatible with M110 barrels and bolt carriers, and utilizes many of the same parts as the legacy bolt design. These improvements to the SR-25 bolt refl ect and support the density of fire required of dual-role 7.62mm carbines in training and real-world application.
Optimized design with dual ejectors that provide increased force and improved ejection consistency, especially notable when experiencing increased bolt carrier velocity due to suppressed fire. Ejection force is increased by over 30% compared to a single ejector bolt, forcing the spent casing out of the receiver faster and more efficiently. Placement of the ejectors ensures that the head of the fi red case does not drift inward, which keeps the center of gravity of the ejecting case further out of the ejection port, preventing spin-back and forward ejection. The dual ejector design allows for increased reliability and redundancy, as the ejector will still function even if a complete ejector and ejector spring are missing or damaged. The lower tension of the dual ejector design lengthen the life expectancy over a single ejector bolt spring by over 50%, allowing the weapon to be in service longer before requiring armorer level maintenance
Enhanced Durability: Stress riser mitigation in the lug areas of the bolt significantly reduces stress on the bolt lugs duringfiring and extraction, extending usable life. This is especially noticeable on the lugs adjacent to the extractor, which are subject to the most continuous stress during firing and extraction. The increased strength bolt design has been proven in testing to exceed 20,000 rounds of live-fire.
Enhanced Value:
• Backward-compatible with the Mk 11 series and M110 series.
• Lowers cost of repair and replacement parts due to reduced part cost and increased part life.
• Reduces maintenance burden, as rifles will be operational for longer intervals before requiring overhaul.
