Marking rounds were invented by Kerry T. Bowden to allow trainees to see where each projectile landed. Much like paintball and simunitions, these marking pellets would break upon impact, marking the target with luminescent liquid. Unlike traditional plastic pellets, marking rounds are heavier to ensure breakage of the shell on impact. The weight can be adjusted by adding heavier liquid. Marking rounds are critical for trainees because they allow the shooter to see exactly where they hit the target. This allows them to extrapolate their mistakes and improve their aim.