Light and Deadly

I belly-crawled into the shade of some low sagebrush near the crown of a swell in the land. Lying low, I stopped to catch my breath and take a look. Immediately, I saw tiny white patches glowing like pearls in the low rays of the early morning sun. Easing up the binoculars, I spun the focus wheel until one of the white pearls materialized into a well-defined antelope with a telltale elongated black face patch extending into a good set of horns.

He was too far away for a shot, but the undulations and ravines in the prairie provided the opportunity for a stalk. About an hour later, I held my breath as I cradled the 6mm Ruger rifle in my arms, military style, while I low-crawled the last few feet to the top of a small ridge. I expected to be in shooting range when I reached the crest if the antelope had not moved, and sure enough, the buck was still there.

I pushed the rifle forward, then back into my shoulder, aligning the crosshair on the rear edge of the buck's chest as he angled away about 200 yards distant. The rifle's report startled the band of antelope into an all-out run, but it was too late for the buck. The 6mm Rem. load sent a Barnes 90-grain X-Bullet through its chest at the back rib, penetrating fully and exiting in front of the opposite shoulder. The buck ran 50 yards and went down in a heap.

It is often written that cartridges sporting .243 caliber bullets are minimal for deer and antelope-size game. They are said to be good combination varmint/deer cartridges. These rounds are also reported to be great for young, slight-of-stature or beginning shooters. The reason? Relatively mild report and recoil encourage good shooting without a flinch.

The thing to keep in mind, however, is that .243 bullet diameter rounds such as the .243 Win., 6mm Rem. and .240 Wby. Mag. are not endowed with an overabundance of energy. For example, a 165-grain .30 caliber bullet going 3,000 fps is packing about 3,300 ft.-lbs. of energy while a 100-grain .24 caliber bullet traveling the same speed carries about 2,000 ft.-lbs.

These are muzzle energies we're talking about, and in the case of the .243 Win., getting even 3,000 fps from a 100-grain bullet takes a maximum load and a decently long barrel, not one of the 18- or 20-inch tubes popular on some of the short-barreled carbines. Deer are not shot at the muzzle, and as a .243 bullet leaves the barrel, kinetic energy falls off fast, depending on the shape of the bullet.

Using computer ballistics programs, one can see that the 400-yard differences between the .243 Win., 6mm Rem., and .240 Wby. Mag. are small in wind deflection and trajectory. With all rifles zeroed at 200 yards, only 2 1/2 inches of trajectory and about an inch of wind drift separate the .243 Win. from the .240 Wby.