phaessler,
On the pressure thing --- I wasn't trying to insult you, I was honestly concerned, pressure signs in shotguns and pressure signs in rifles are not the same.
On the down range Chrony thing --- Yes, if you know a bullets B.C. you can indeed just do the math to figure down range velocity and energy. However, if you don't know the B.C. you e-mail the mold manufacture and they admit "they don't have that information available" and just give you an educated guess the only way to accuratly determine the B.C. is to measure the projectiles velocity at two different points in it's flight path. The farther appart those two points are the more accurate will by the experimentally determined B.C. The manufactures do something very similar under significantly more controlled conditions (fixed/mounted pressure guns with known down range impact points) to come up with the most accurate B.C. for their bullets. I'm not talking about shielding the slug just from wads and other debree, I'm talking about completely shielding the Chrony to protect against even a direct hit with a way-ward slug regardless of whether it be operator error or a flier produced by component failures.