The Sterling pump action marker was often called the Rolls Royce of paintball guns. Dave Galsworthy built the first prototype of the Sterling in 1989 and it was formally launched at the 1990 Nashville Masters tournament.
The Sterling is a stacked tube design with the bolt and barrel sitting above the valve and hammer. Interestingly, the Sterling uses a very similar hammer and sear to a Nelson style pump. Take down is by two thumb screws in the grip frame and this is a bit of a weak point in the design. Heavy pumping while holding the trigger down in auto trigger mode can cause these screws to come loose and in the worst case cause the marker to fall apart on the field. Velocity adjustment was also an issue on the early models and required spring changes to effect.
Despite these short comings the Sterling was beautifully made, a good performer, had a smooth pump action and better accuracy from its brass lined barrel than its contemporaries.
Dave Galsworthy went on to design a semi auto marker called the Sovereign which was released in 1996. The rights to the Sterling and the Sovereign were bought by Arrow Precision in 1998. The Sovereign is still listed on the Arrow Precision web site today.