NLX-11B 450 Bushmaster Brake (Bear Creek) After creating the NLX556 450 Bushmaster rifle, our team at Next Level Armament knew we had to find a solution to the heavy recoil and muzzle rise we experienced. We designed and tested several prototypes searching for the best performance. The original NLX-11 450 brake was born! Customers asked for other thread sizes for different barrel manufacturers, and we listened. We precision machine each NLX-11B 450 Bushmaster Brake from 4140 stainless steel raw stock and Nitride finish for a durable, long lasting part. Specifically designed to reduce recoil and muzzle jump, the NLX-11B enables the operator to achieve greater accuracy and deliver better follow-up shots. Whether hunting hogs or hunting deer, your 450 BM rifle needs the best brake in the industry. Your shoulder will thank you! Details: 2.5' Long, .88' Diameter. Thread size 5/8 x 32. *Installation notes: Due to the large diameter of the 5/8 x 32 Bushmaster barrel threads, the crush washer is relatively thin compared to traditional .308 and 5.56 crush washers. We recommend hand tighten, then index using no more than 1/3 turn. If you over-tighten past 1/3 turn, you may snap the crush washer. Due to different thread points between barrels, do not try to index simply by our logo. We designed our brake to have a solid 'ridge' up with port holes at 11 and 1 o'clock.*