Early Whitney revolvers, for example, were similar to the Remington, but lacked safety slots between cylinder chambers.

It was possible to lower the Whitney hammer between cylinder chambers for safe carry.

Later production Colt M1917 revolvers had headspacing machined into the cylinder chambers, just as the Smith & Wesson M1917 revolvers had from the start.

The factory proof-fires each cylinder chamber with .357 Magnum ammunition generating 30% more pressure than the C.I.P. maximum allowable pressure for the Magnum cartridge.

A pivoting lever on the side of the upper receiver is pressed to release the cylinder-barrel section, which tilts up and forward ("breaks") on a bottom-front pivot, simultaneously ejecting the contents of the cylinder chambers.

"We've got company" Austin said as he checked the five-shot cylinder chamber.

Firstly ground coffee is dosed into the cylinder chamber.

Then the cylinder chamber is closed by the upper piston, which moves above the chamber then down to seal it.

Hot water is passed through under pressure, coming from the back of the mechanism via the lower piston, through the ground coffee in the cylinder chamber.

The lower piston then moves upwards, pushing the coffee residue out of the cylinder chamber.