This third generation 9mm bolt assembly eliminates the need for a central mass (slug) to readily function with the 9mm JP Silent Captured Spring without compromising bolt weight and reliability. In fact, when combined with a Silent Captured Spring, you have the most reliable 9mm operating system that dramatically reduces bolt bounce while improving accuracy. In addition to use with the JP full-stroke Silent Captured Spring, this revision is now compatible with their line of short-stroke Silent Captured Springs. This bolt assembly will provide reliable last-round lockback with any compatible receiver.
