This program was led by Philadelphia and Western's vice-chairman W. L. Butler, who had been largely responsible for development of the Cincinnati and Lake Erie Railroad's Red Devil car design, in collaboration with the J. G. Brill Company.

Their design was improved over earlier styles of railcars after a lot of wind tunnel research – the first in the American railway industry[4] – the Bullet was streamlined to minimize the air resistance.

According to Felix W. Pawlowski of University of Michigan, this would save 40% or more of the energy required by the conventional type of passenger car at speeds in excess of 60 mph (97 km/h).

The Bullets as built for the P&W were longer at 55 feet (17 m) and a bit heavier at 26 short tons (24 t), but with only about half the weight of typical railcars of that time.

To further utilize the Bullets' potential, more improvements were made to track and signal systems to permit extremely high speeds on the Norristown line.

[2]: 108 In a test run one of the cars traveled the 13.5-mile (21.7 km) P&W line from Norristown to the 69th Street Terminal in Upper Darby in 11 minutes[2]: 70  while in regular passenger service they cut express schedule timings by 1/3, from 24 to only 16 minutes including stops, running at 80–90 mph (130–140 km/h) P&W bought ten double ended, multiple-unit Bullets.

[7]: 186  Five shorter 47 feet (14 m), single ended, single-unit Bullets with a slightly different front and rear design were sold to Fonda, Johnstown and Gloversville Railroad (FJ&G) in 1932.

The decline of the interurban business as a result of the Great Depression of the 1930s and increasing use of automobiles and buses precluded further manufacture and sale of the Bullet cars.

[8] FJ&G's bright orange Bullets ran hourly into Schenectady where they terminated in front of the New York Central railroad station.

The five Bullets went to the Bamberger Railroad (BR) interurban in Utah and served the line from Salt Lake City–Ogden hourly, although operating at lower speeds than on the FJ&G.

Different kinds of MU equipment in use on the Norristown line later resulted in the Bullets' being restricted to less busy times (weekends) when the ten of them could provide 100% of the service.