Pronghorn Antelope Cartridges
By Chuck Hawks
The North American pronghorn antelope is a relatively small, lightly built speedster about the size of an African impala. Average live weight is about 80-100 pounds, and what would be called a big pronghorn might scale 110 pounds. The very largest pronghorns might attain 150 pounds, but antelope that large are very rare.
Because pronghorn are relatively small, light framed animals, rifles of great power are not required for humane kills. Pronghorn antelope are CXP2 category game. A quick opening big game bullet (not a varmint bullet) with a good ballistic coefficient is an appropriate choice. Examples of suitable bullets would include the Hornady SST, Nosler Ballistic Tip, Remington Bronze Point, Sierra GameKing, Speer Hot-Cor SPBT, Swift Sirocco, and Winchester Ballistic Silvertip.
Most of all, the hunter must get that adequate bullet into a vital spot (usually the heart/lung area) of the antelope. The cartridge recommendations that follow assume such a shot.
Antelope are plains animals that usually favor open country and are therefore typically hunted with long range, flat shooting rifles. The average shot at pronghorn is probably taken between 200-300 yards. However, like most animals, pronghorn antelope can be adaptable, and there are places in my home state of Oregon where they inhabit the forested eastern slopes of the Cascade Mountains. In such an environment ranges are much shorter, and rifles of the .30-30 class are entirely adequate. Basically, a rifle that delivers a .24 inch or larger diameter bullet with a sectional density of about .215 or better and approximately 800 ft. lbs. of remaining energy at impact will do for pronghorn. But because antelope hunting is usually thought of as a relatively long range sport, the cartridge recommendations that follow will focus on relatively long range cartridges.
For most of the 20th Century the .250-3000 Savage (introduced in 1915), the .270 Winchester (introduced in 1925), and the .257 Roberts (introduced commercially in 1934) were highly recommended antelope cartridges, and they still are. These flat shooting numbers, when equipped with telescopic sights, really opened hunters' eyes to what high velocity cartridges could do. More recently, a plethora of cartridges has been added to the mix.
I think it might be wise to divide pronghorn cartridges into two categories. The first category will include cartridges with a +/- 3" maximum point blank range (MPBR) of greater than 270 but less than 300 yards. Most of these are all-around cartridges intended for variety of CXP2 and CXP3 class game that offer an adequately flat trajectory for antelope hunting with appropriate loads (usually the lighter weight bullets for the caliber). I will call these "Adequate cartridges."
The second category are "Long range cartridges" featuring a MPBR of 300 yards or more with appropriate loads. If you are specifically planning an antelope hunt it is this second category of cartridges that may be of special interest.
Many of these cartridges are more powerful than necessary, and few shooters can shoot them as well as the cartridges more specifically recommended for pronghorn hunting. Never the less, they shoot flat enough with the right loads to get the job done.
Long range cartridges
The .240 Weatherby, .257 Weatherby, 6.5x68, .264 Winchester and .270 Weatherby feature MPBR's greater than 320 yards. These are top choices if ultra-long range shots absolutely must be taken.
I have not tried to list every possible pronghorn cartridge in the categories above, they are merely examples of typical satisfactory cartridges. If a cartridge is not listed it does not mean it is no good. Look for a cartridge with similar ballistics. If you find one, then the cartridge in question is also probably adequate.
Cartridges more powerful than the .30-06 not listed here because they are so far into the "over kill" zone that it is more punishment than pleasure to hunt creatures as diminutive as antelope with them. This specifically includes the various 7mm and .300 Magnums. These shoot flat enough to get the job done, but burn way too much powder to be sensible for the purpose.
Considering the long range rifles usually recommended, pronghorn hunting puts more emphasis on marksmanship than most big game hunting. Even the best equipment must be used wisely. It is always better to take the time and make the effort to stalk within 200 yards than to blaze away at 400 yards. If a stalk to within certain kill range cannot be made, it is best to pass up the shot.
Do not shoot at running antelope. Pronghorn are among the fastest land animals on earth, and can run at speeds of 50-60 MPH. The lead required at such speeds is fantastic; many hunters have fired at the lead animal in a group and hit the second or third. It has been estimated that more pronghorn antelope escape wounded to die later than any other big game species. Hunters who shoot when they think they have a good chance of connecting rather than waiting until they know they can make a one shot kill are to blame for this.
No one can shoot better than they can see, so a high quality telescopic sight is a practical necessity for the modern pronghorn hunter. A fixed 6x scope, or a variable power model in the 2.5-8x, 3-9x or 3.5-10x range will do nicely. The rifles in my personal battery that I would most likely choose to take on an antelope hunt are my .240 Weatherby, which wears a Leupold 3-9x scope, and my .257 Weatherby, which wears a Weaver Grand Slam 3-10x scope. Either would be excellent for the purpose.
Copyright 2006, 2010 by Chuck Hawks. All rights reserved.