Upon its introduction, the Confidence Clip solved an ongoing need to improve hand grenade safety. The Confidence Clip is a device designed to fit between the fuze and grenade body, securing the safety pull ring and preventing it from accidentally coming loose and arming the grenade.
A manual installation of the Confidence Clip began with the existing 15 million inventory of M228 practice grenades. Each grenade had to be disassembled and reassembled to install the Confidence Clip. The completion rate of this manual installation was one grenade in 40 seconds, which would roughly require 17½ years to replace the entire M228 existing inventory.
NCDMM and its partner, Kinemetrix – Agile Automation worked with the Blue Grass Army Depot (BGAD) and the Armament Research Development and Engineering Center (ARDEC) in the development of a process and design of an automated machine to install the Confidence Clips.
As a result of the process and the automated machine designed and developed by NCDMM and Kinemetrix, grenades can now be retrofitted at a rate of 17 per minute with the entire M228 inventory retrofitted in 7 years. This completion rate directly translates into a cost avoidance of $14.9 million over 7 years. It also accelerated the timeframe for when Confidence Clip can be installed next into real fragmentation hand grenades like the M67.