Frame for a firearm

What is this patent about?

’574 is related to the field of firearm architecture, specifically focusing on compact, manually operated repeating firearms. The background context addresses the need for shorter overall weapon lengths without sacrificing barrel length, particularly for secondary weapons mounted under a primary rifle. Traditional designs require long receivers to accommodate the rearward travel of a bolt during cycling, which creates unused internal volume and increases the weapon's footprint.

The underlying idea behind ’574 is a reversal of the standard operating cycle by utilizing a stationary bolt and a forward-sliding assembly. Instead of the bolt moving backward to extract and load shells, the barrel and receiver are joined into a single unit that slides forward away from the shooter. This engineering insight eliminates the need for a long, hollow receiver housing, allowing the breech to be positioned at the very rear of the frame and significantly reducing the firearm's total length.

The claims of ’574 focus on a specialized firearm frame that acts as a stable platform for this inverted movement. The frame includes an elongated support structure—specifically two spaced-apart rails—that directly guides the movable barrel and receiver assembly. The independent claims also cover the integration of a trigger assembly that is mounted to and moves with the sliding receiver, yet remains capable of operatively engaging the stationary firing mechanism when the action is closed.

In practice, the invention functions through a unique separating sear mechanism. Because the trigger moves forward with the pump action while the hammer and firing pin remain stationary on the frame, the mechanical link between them must physically disconnect and reconnect. When the user slides the forearm back into the retracted position, the trigger link re-establishes contact with the sear lever, allowing the weapon to fire only when the action is fully locked in battery.

This approach differs from prior art by moving the fire controls to a forward position, allowing the operator to cycle and fire the weapon using their support hand without shifting their grip. By mounting the stationary firing components to a rigid frame that can be attached to a primary rifle or a standalone stock, the design achieves a compact form factor that maximizes barrel efficiency and improves ergonomics for high-stakes tactical environments like door breaching.