Within its effective range, the .17 Mach 2 offers plenty of punch for hunting small game. Fox squirrels are tough critters, but the first two I shot through the lungs at about sixty yards toppled from the same tree and appeared stone dead before they reached the ground. Meat damage was no worse than with .22 Long Rifle ammo.

A few hunters use .22 Long Rifle match ammo (left) on small game by shooting extremely accurate rifles and sticking with head shots only--but the high-velocity version (center) is more popular. The Stinger load (right) is best reserved for varmints.

Over the next few days I made body shots as far away as 130 yards, and while I did not lose a single bushytail, I could tell I was beginning to push my luck at that distance. With solid hits, the .17 Mach 2 kills California ground squirrels dead in their tracks out to 150 yards, but longer shots become iffy as the velocity of that tiny bullet drops off to the point where it begins to lose its ability to expand explosively.

You can duplicate .17 Mach 2 accuracy with .22 Long Rifle match ammunition such as Eley Tenex, but regardless of how that type of ammo is zeroed, it does not shoot flat enough for consistent hits once the range greatly exceeds fifty yards.

You can come close to duplicating .17 Mach 2 trajectory with hyper-velocity .22 Long Rifle loads, but the mediocre accuracy of those loads in some rifles can restrict their practical use on small game to about fifty long paces. When it comes to delivering the entire package--accuracy, trajectory, energy and the ability to buck wind--the .17 Mach 2 outguns any .22 Long Rifle load presently available for use on small game.

.17 Hornady Magnum Rimfire (HMR)
The .22 Winchester Magnum Rimfire case necked down, the .17 HMR is loaded by Hornady, Federal, CCI and Remington with a seventeen-grain bullet at 2,550 fps (CCI also offers a twenty-grain Gamepoint load at 2,375 fps). The cartridge delivers almost 25 percent more energy at 100 yards than the .17 Mach 2, but at that distance it falls short of the .22 WMR by about the same amount.

DESTINED TO BECOME A CLASSIC

What do you get when you combine Weatherby quality with Anschutz accuracy? If your answer is the new Weatherby Mark XXII, take a seat at the front of the class. Unlike the Weatherby autoloading .22 of yesteryear with the same name, this one is a bolt-action in .22 Long Rifle or .17 HMR. Anschutz builds the barreled action in Germany, and it's stocked in America by Weatherby. With its high-gloss walnut stock replete with Monte Carlo-style cheekrest, it looks a bit like its big brother, the Weatherby Mark V. Other features include eighteen-line cut checkering, a match-grade 23-inch barrel, a fully adjustable trigger and a steel trigger guard. The receiver is both grooved and drilled and tapped for scope mounting. The magazine is detachable with a capacity of 5 rounds in .22 Long Rifle and 3 rounds in .17 HMR; an optional .22-caliber accessory magazine holds 10 rounds while the .17-caliber version holds 4. Nominal weight is 61?2 pounds and suggested retail is $899. The two I shot averaged less than half an inch for five shots at fifty yards. This is a very nice rifle and one worthy of the Weatherby name: www.weatherby.com.

The .17 Mach 2 is a better small game cartridge and the .22 WMR is better for larger targets such as woodchucks and turkey gobblers, but the .17 HMR's flatter trajectory gives it about a twenty-five-yard advantage on small varmints such as flickertails, ground squirrels and prairie dogs.

The biggest competitor to the .17 HMR is the .22 WMR loaded with bullets in the thirty- to thirty-three-grain weight range. For starters, average cost for .22 WMR ammo is about 30 percent less than for the .17 HMR. The .22 WMR is also loaded by CCI with fifty-two grains of No. 12 shot, a pest load option we will never see offered for the .17 HMR. But the .17 HMR shoots flatter.

With my rifle zeroed two inches high at 100 yards, I can hold on the head of a ground squirrel standing erect at 200 yards and place the bullet precisely. Considerably more Kentucky elevation is needed when reaching out that far with the .22 WMR. Inside fifty yards there is very little difference in the effectiveness of the two cartridges on varmints up to the size of prairie dogs, but as the range is increased to 100 yards and beyond, the heavier bullet of the .22-caliber cartridge begins to show its superiority.