Abstract: A modular firearm system has a frame with a grip configured to be held by a hand of a user and a receiving chamber formed within the grip. The system further has a chassis having a receiving channel and one or more sidewalls extending from a bottom portion of the chassis, the one or more sidewalls structured to fit within and be received by the receiving chamber of the frame. The system further has a barrel locking block structured to fit within the receiving channel of the chassis.

Abstract: A hook for deploying a pin-and-lever detonation device, such as a flash bang grenade, and a method for use of the hook, is disclosed. The hook includes a base for attaching the hook to the side of a firearm, such as at a hand guard, grip, body, or accessory rail. It further includes an arm extending substantially laterally from the base. A recess is defined between the base and the arm, structured to receive a pull-ring of the pin-and-lever detonation device and provide leverage for a user pulling the pull-ring. A lip is formed at an end of the arm, structured to curve away from the arm and guide a pull-ring of the pin-and-lever detonation device into the recess. The disclosed hook enables an operator to deploy a grenade one-handed while simultaneously keeping his firearm readily available and covering his own person.