Straight pull rifles are not new. The concept and a wide variety of designs have existed since the 1800s and are known for fast cycling times and easy handling. Straight pulls differ from traditional bolt actions in the way that a shooter cycles the bolt. After a round is fired in a traditional bolt action, the bolt handle must come up, then move back, then forward and then down again. Straight-pull actions eliminate half of the motions, requiring only the backward and forward motions. Yet early straight-pull designs left many wary of reliability and safety. If the bolt is free to travel in a straight line and doesn’t have the added security that comes from cranking a bolt handle down into a slot in the receiver, it stands to reason that the bolt could fail and fly back at the shooter. This fear was enough to scare some shooters away from the design. This issue was at the heart of our design challenge when we tackled Impulse. The solution? Hexlock, a proven ball bearing locking mechanism.

How Hexlock Works

When Impulse’s bolt handle is fully closed, a plunger is seated forward in the interior of the bolt body, forcing six ball bearings outward to lock into a machined recess in the barrel extension. When a round is fired, the symmetric ball bearings tighten relative to pressure increase and provide a robust lockup for safety. In contrast to blow back rifles, Hexlock utilizes a plunger that is ramped, so that as pressure increases, the ball bearings are driven outward locking them into the recess in the high strength barrel extension. The strength of Hexlock allows the rifle to handle magnum cartridges and high-pressure rounds. Extensive testing has been done to develop the safety enhancements and every rifle is proofed to industry standards.

After a round is fired, pressure subsides, and the bolt is ready to be cycled. As the bolt handle is opened, the plunger recedes and releases the ball bearings, allowing the action to be opened. This entire process happens in a fraction of a second. When the action is cycled to the rear, Impulse has a robust bolt stop in the receiver that is designed to absorb the energy of a bolt that is traveling rearward to protect the operator. The bolt is then ready to be cycled forward back into firing position. Combined with the ergonomic backward and forward motions to cycle the bolt, Impulse lives up to the straight-pull legacy of being fast and easy to handle.

Hexlock is also designed to prevent Impulse from firing out of battery. A properly serviced and maintained Impulse using factory produced ammunition cannot fire out of battery. This is due to the arrangement of the internal mechanisms and the interaction with the striker, plunger, and ball bearings. In other words, the rifle cannot fire without everything being in the proper location. If the plunger is not fully forward, it will impede the striker reaching the primer and prevent firing. The plunger must be all the way forward. This means that the ball bearings must be properly expanded in the extension and in battery for firing to occur.

For shooters concerned about carbon build-up and causing Hexlock’s ball bearings to get dirty and fail…we have good news! You don't have to clean Impulse more than any other bolt gun. Due to the design, there is not any significant gas passing over the lock up to cause build up or debris because the bolt is closed off and protected during normal cycling. Even if enough dirt or debris were to get into the critical areas, the system allows for some clearance, so the ball bearings would just push debris out of the way and maintain a robust lock up. 

The Impulse action locks the bolt handle in the firing position to prevent unintentional opening of the action while the rifle is cocked. Once the rifle is fired the bolt handle is no longer locked and the action can be opened quickly and smoothly. Any time you want to open the action without firing such as checking the chamber or ejecting a live round Impulse has a single-step quick-release button on the back end of the bolt which can be used to unlock the bolt handle. In either case, Impulse’s rotary bolt handle aids in primary extraction, giving the bolt operation a mechanical advantage. The best way to cycle the action is with the firearm shouldered, as the shape of the handle and stock places the shooter in the optimal position to efficiently work the action. 

With its inherent safety, speed and accuracy, Impulse provides an entirely new option for anyone looking for a competitive edge.