Mule deer are the second most widely distributed deer species in North America. In the US they are commonly thought of as western deer and they are hunted in almost all of the western states. As a species, the mule deer has been genetically proven to be a variation of the Columbian blacktail deer (the exact opposite of what was previously believed) and where ranges overlap, the two species freely interbreed. The state in which I reside, Oregon, arbitrarily considers all deer taken west of the summit of the Cascade Mountains to be blacktails and all deer taken east of the Cascade summit to be mule deer. Mule deer range (and there are several subspecies) basically extends from the eastern slopes of the Cascade/Sierra Mountains all the way across the Rockies to the great plains of Canada and the US, as well as down into western Mexico.

Mule deer are thin-skinned (CXP2 class) game. They are, on average, the largest species of North American deer, normally weighing about 150-200 pounds on the hoof, depending on species, location and the size of the individual animal. Even a very large mule deer rarely exceeds 300 pounds. Mule deer are not particularly hard to kill with a well placed bullet, but they can be a problem to collect if wounded.

Any centerfire rifle cartridge that will legally and reliably kill a blacktail or whitetail deer will also kill a mule deer. However, some calibers are clearly more appropriate for mule deer hunting than others. In general, mule deer are thought of as a relatively long range proposition, because over much of their range they favor mountainous and relatively open terrain that often offers good shooting lanes. Unlike the blacktail from which they descended, mule deer are typically not inhabitants of the deep woods or coastal rain forest. There are exceptions, to be sure, but for the purposes of this article I am addressing classic, open country mule deer hunting.

That being the case, experienced mule deer hunters today tend to favor flat shooting cartridges over traditional numbers like the .30-30, although a great many mule deer have fallen to .30-30 rifles. Long range cartridges between .24 and .30 caliber are most commonly recommended. Since mule deer are CXP2 game, I have eschewed the 7mm, .300 and 8mm Magnums as unnecessarily powerful, although they will certainly dispatch mule deer with ease. Likewise, the powerful medium bore and large bore calibers intended for heavy and dangerous game are not included here. These ultra-powerful cartridges are simply unnecessary and generally counter-productive.

A mule deer cartridge should deliver about 800 ft. lbs. of kinetic energy at whatever range the bullet impacts. The cross-sectional area of the bullet should be at least .0464 square inch. The sectional density of a good, small bore (.30 caliber or less) mule deer bullet should be at least .215 for adequate penetration and ballistic coefficient. Soft point or plastic tipped bullets that expand well against light resistance, such as the Hornady Interlock, Nosler Ballistic Tip, Remington Core-Lokt, Sierra Pro-Hunter and GameKing, Speer Hot-Cor and Winchester Power-Point, will usually deliver the quickest kills.

Most of the mule deer cartridges recommended below have a MPBR of at least 250 yards and some have a MPBR in excess of 300 yards. In most cases, medium-light weight spitzer bullets (90-100 grain in .24 caliber, 100-115 grain in .25 caliber, 120-140 grain in 6.5mm, 130 grain in .270 caliber, 140 grain in 7mm and 150 grain in .30 and .303 caliber, for example) are good choices for mule deer hunting.

Please bear in mind that when recommending mule deer cartridges and loads, I am assuming that the hunter uses a bullet of adequate weight, sectional density, expansion characteristics and gets it into a vital spot (usually the heart/lung area of the deer). Bullet placement is, always, the most important factor in killing power.

It would be impossible to list every possible mule deer cartridge and I would inadvertently leave out someone's favorite. The cartridges mentioned below are examples of satisfactory cartridges. If a cartridge is not listed, it does not mean that it is no good. Look for a cartridge with similar ballistics. If you find one, the cartridge in question is also probably adequate. Okay, here are some reasonable mule deer cartridges:

.243 Win., 6mm Rem., 6x62 Freres, .240 Weatherby Mag., .244 H&H Mag., .257 Roberts, .25-06, .257 Weatherby Mag., .260 Remington, 6.5x55 SE, 6.5mm-284, 6.5mm Rem. Mag., 6.5x68S, .264 Win. Mag., .270 Winchester, .270 WSM, .270 Weatherby Mag., 7mm-08, 7x57, 7x64 Brenneke, .280 Remington, .300 Savage, .308 Marlin Express, .308 Winchester, .30-06, .303 British and 8x57JS.

Note that cartridges on the order of the 6.5mm and .270 Magnums, while excellent mule deer calibers in other respects, intimidate many hunters with their recoil and muzzle blast. (Not many shooters will 'fess up to that, but it is true.) Recoil is inversely proportional to rifle weight, so if your ideal mule deer rifle is a lightweight mountain rifle, pick a moderate cartridge. Most mule deer hunters will do very well (and shoot better) with cartridges such as the .257 Roberts, .260 Remington, 6.5x55, 7mm-08 and 7x57.

In closing, let me reiterate that mule deer are neither huge nor particularly hard to kill and bullet placement is the most significant factor in killing power. A good shot with a .257 is a far deadlier mule deer hunter than a man shooting a 7mm Magnum that causes him to flinch. Choose a rifle of appropriate weight chambered for a reasonably adequate caliber that you can shoot well. Use an appropriate bullet within its energy and trajectory limits. Most of all, get that bullet into a vital spot if you want to bring home a trophy rack.