Years ago, I often traveled to and from Europe and the Middle East on both the British and the French Concorde airliners. A large monitor at the front of the passenger's cabin constantly indicated in large green letters the speed of that wonderful airplane.

As the sleek craft leveled off at just over 58,000 feet at the beginning of my very first 3.5-hour flight from Washington to London, "MACH 2.04" flashed on the monitor. So I whipped out my portable calculator and started punching its keys.

Always a shooter at heart, I was curious to compare my twice-the-speed-of-sound velocity to that of a rifle cartridge. I remember the thrill I felt when the little instrument in my hand showed me I was traveling faster than a 170-grain bullet fired from the .30-30 Winchester by a deer hunter who might be standing miles below me.

I was reminded of those long-ago Concorde flights when I first heard about a new cartridge from Hornady called the .l7 Hornady Mach 2 (HM2). How they came up with the name is no great mystery. The speed of sound traveling through air at sea level is said to be around 760 miles per hour, or 1,115 feet per second, so Mach 2 works out to roughly 2230 fps. Hornady rates the itsy bitsy cartridge at 2100 fps, so if we flatlanders want to be technically correct, we would call it the ".17 Mach 1.9" or something like that. But since that moniker sounds as awkward as calling the .44 Magnum the .429 Magnum, Hornady wisely chose to make things short and sweet by naming it the .17 HM2. That worked out quite nicely since it is indeed a sweet little cartridge--and it is also quite short.

ACCURACY & VELOCITY COMPARISION
FACTORY LOAD	VELOCITY (fps)	100-yard ACCURACY (in.)
	.17 HM2 Kimber 17 Pro Varmint, 20 Inch Barrel
CCI 17-gr. V-Max	2083	1.25
Eley 17-gr. V-Max	2178	1.37
Federal 17-gr. V-Max	2155	0.95
Hornady 17-gr. V-Max	2113	1.29
Remindton 17-gr. AccuTip-V	2108	1.18
	.22 LR Kimber 22 Pro Varmint, 20 Inch Barrel
CCI 32-gr. Stinger	1634	2.01
CCI 40-gr. Velocitor	1364	1.36
Federal 40-gr. Classic	1236	1.19
Remington/Eley 40-gr. Match EPS	1064	0.71
Winchester 38-gr. Power-Point	1282	1.20
Notes: Accuracy is the average of five, five-shot groups fired from a sandbag benchrest at 100 yards. Velocity is the average of 25 rounds measured 12 feet from the rifles' muzzles.

Just for the fun of it, and to give people who take life far too seriously something to complain about, I will also point out that whether or not the .17 HM2 lives up to its name in velocity depends on who is shooting it and where it is being shot. Since the speed of sound decreases as elevation above sea level increases, the 17-grain bullet fired from the rifle of a Sherpa porter standing 29,000 feet above base camp on Mount Everest would actually leave the muzzle at a speed greater than Mach 2.

One thing is certain, if the speed at which rifle and handgun manufacturers geared up to start chambering for the .17 HM2 could somehow be measured, it would likely prove to be even faster than twice the speed of sound. Quicker than you can say, "I love the .17," each and every manufacturer of .22 rimfire rifles and handguns was chambering for the little round.