223 / 5.56 Bionic Bolt Assembly, MPI
ADK Arms bolts are built to the limits of durability and craftsmanship enduring extreme testing and service in the field. Each part features magnetic particle inspection (MPI) and our high quality nitride QPQ finishing.
- 9310 Heat treated (case hardened to SAE-AMS-6875) with additional cryo freeze for extra strength.
- Shot peened precision ground diameters.
- Magnetic particle inspected to ASTM E1444 aircraft quality inspection procedure for molecular soundness and longer life of the Bolt.
- QPQ nitride coating
- Aircraft quality alloy steel shot peened.
- Heat treated to military drawing specification SAE-AMS-6875.
- Phosphated to 18.104.22.168 of MIL-STD-171.
Enhanced Extractor Springs
To assure the highest degree of consistency and reliability, ADK Arms invests in premium extractor springs from Tactical Springs LLC / Sprinco USA along with a Mil-Spec Black Viton Extractor O-Ring per MIL-R-83248C. The springs are constructed from Chrome Silicon wirestock, a high tensile strength alloy ideally suited for high heat and high cyclic rate applications. The springs are heat treated, stress relieved, moly-plated, and most importantly, Cryogenic Processed post winding. While Cryogenic Processing typically extends the duty cycle of Chrome Silicon springs 3X – 7 X, these extractor springs have proven to surpass that multiplier. Unlike Music Wire or 17-7PH Stainless extractor springs which can require replacement at 2,500 to 5,000 round intervals for maximum reliability, this is likely to be the only extractor spring you’ll require for the life of the bolt! Numerous accounts have been recorded from customers with round counts in excess of 100,000 cycles on a single spring and O-ring with no noticeable degradation in performance. You’ll go through a number of barrels and extractors along the way to reaching that level, but the spring and O-rings can stay along for the ride.