Good day all. I just thought I would add this to the site. Very interesting for those that like number crunching. Much thanks to Mr. Richard Walbaum of Paintball-Gun-Review.com. Much thanks to his contribution. This is for gravity feed markers with no force feeding device. Also, for those that have angled or power feeds, you really cannot accurately calculate how fast feeding can be given the air that can be exhausting up into the feed port, what a power feed needs/uses to feed quickly.

How Fast Can a Gravity-Fed Hopper Theoretically Feed a Marker? Answer: 16.7 balls per second. Calculations are shown below.

How fast can a gravity fed hopper (as distinguished from a force-fed hopper) theoretically feed paintballs into the breech of a gun? The maximum rate would be determined by how quickly gravity could move a paintball from its position just above a closed bolt, and into the breach once the bolt opens.

It is assumed that the paintball starts from a sitting position above the closed bolt; i.e., the velocity is zero. No assumption is made about the diameter of the paintball.

The distance an object will fall under the influence of gravity is defined by the equation:

d = (1/2) g t²

Where:

g = the acceleration due to gravity, a constant 386"/sec²

d = the distance the object falls; in this case the paintball must fall the diameter of one paintball, typically 0.689".

t = the time it takes to fall the distance of one diameter d, in “seconds per ball”.

We want "balls per second" (bps), so by rearranging terms and taking the inverse:

bps = 1/t =(g/2)^1/2/d^1/2

The ^1/2 superscript means "square root".

g/2 is a constant = 193”/sec²; taking the square root gives 13.9, resulting in:

bps = 13.9/d^1/2

In conclusion: To calculate the maximum gravity feed rate for a hopper use the equation:

bps = 13.9/d^1/2 where d = ball diameter

For a given ball size of 0.689", we can calculate the maximum rate to be:

bps = 13.9/(.689")^1/2 = 16.7 balls per second

This is the theoretical maximum based on gravity. We also have to add time for the bolt to force the ball into the chamber, fire, it, reopen, and also allow time for new paintballs to enter the feed tube, factors which are not considered here.

About the author: Richard Walbaum is the author of Paintball-Gun-Review.com. His unique site takes reviews from many players and digests them into one review.