When saw cutting lots of parts, shops speed the job by cutting bundles of raw material in one clamping. Bundling works well for square and rectangular bars but not for round stock, especially if the saw is not equipped for holding multiple round bars. In this situation, I use a yoke-style pipe vise.
I C-clamp the yoke vise in front of the blade and use the saw's regular vise to hold a length stop. The bars then feed into the saw from the opposite way. Also, to increase the yoke vise's capacity, I either line or replace the pipe jaws with heavy angle-iron pieces. Another helpful trick is to wrap the bundle of material with fiber-reinforced strapping every foot or so and then saw through it.