John Kelsey wrote

Interesting questions: How hard is it for someone to actually hit an airplane with a rifle bullet? How often do airplane maintenance people notice bulletholes?

Damn hard. There's a reason winghunters use shotguns, and anti-aircraft guns are full auto. The only way an attacker would have a chance is to stand at the end of the runway, and fire while the plane passes overhead. I have heard of police choppers and ultra lights being fired on from the ground, but never a commercial flight in the US. The scenario the gun-grabbers posit is someone doing this with tracer rounds. Commercial aircraft do not have self-sealing tanks, and if the attacker is incredibly lucky he might be able to start a fire. 50 BMG can be effectively used in anti-material roles, but firing on planes in the air is not one of them. Barrett actually tried to make an shoulder-fired AA model at one point, but abandoned it as impractical. As has been pointed out, 50 BMG rifles have never been used in the commission of a felony. They are being demonized because they Look Scary (check out www.barrettrifles.com). Peter Trei