Varmint Cartridges

By Chuck Hawks

Illustration courtesy of CCI.

Most varmints are pesky rodents, infamous for destroying crops. Marmots (ground hogs and rock chucks), ground squirrels, gophers, rats, and prairie dogs are examples of typical varmints. Farmers are usually glad to have responsible hunters shoot these creatures, as their destructive habits directly impact the farm's bottom line profits.

Sometimes small predators such as opossums, foxes and coyotes are also classed as varmints, although in reality they often prey on rodents. Unfortunately, they also prey on small domestic animals such as chickens, turkeys, rabbits, and even cats and dogs. While small predators are often shot with varmint rifles, they are really not varmints in the traditional sense.

As in any kind of shooting sport, safety is paramount. Because varmints are often hunted in semi-populated rural areas, and reckless shooting can put buildings, vehicles, and domestic farm animals at risk, varmint hunters must pay particular attention to what lies beyond the target.

Varmint bullets are frangible, designed to break up if they contact a hard surface. This helps to prevent ricochets. Also, since varmints are small animals, violent expansion rather than penetration is the key to quick kills. For these reasons, and because varmints tend to be wary creatures (particularly where there is substantial hunting pressure), high velocity, long range rifle cartridges are generally preferred.

The most popular small game cartridge is the .22 Long Rifle, and it is often pressed into use against varmints. But it has serious drawbacks. Its low velocity (MV 1255 fps) means that its 40 grain lead hollow point hunting bullets do not break up on hard surfaces and are very prone to ricochet. Low velocity also means that the .22 LR bullet does not expand violently when it hits the target, so its killing power is marginal for the larger varmints. And the trajectory of the .22 LR cartridge is such that its maximum point blank range (MPBR) is limited to about 85 yards. Beyond that distance one must hold over the smaller varmints to hit them. The Hyper Velocity .22 LR cartridges, such as the CCI Stinger, are superior to the normal High Velocity .22 LR rounds, but are still far from perfect. They are, however, the best ammunition choice if a .22 LR rifle is to be used for varmint hunting.

All in all, the .22 LR is a satisfactory varmint cartridge only at relatively short range, for use on small varmints, and where there is a very safe backstop to catch possible ricochets. The .22 LR's catalog energy at 50 yards is 110 ft. lbs.

On the plus side, the .22 LR is a very quiet cartridge and tends not to alarm people in semi-populated areas. This is ironic, as, due to its propensity to ricochet it is actually far more dangerous in such locations than much noisier and more powerful cartridges such as the .220 Swift, whose high velocity bullets will break up on even light resistance.

In the same general class as a varmint cartridge is the .17 Mach 2. This newer rimfire is based on the Long Rifle case necked down to accept a 17 grain, .172" diameter spitzer bullet. The MV of this load is 2100 fps. It offers higher velocity and flatter trajectory than the .22 LR, but even less killing power beyond 75 yards due to its lighter bullet of smaller cross sectional area. The .17 Mach 2 features a MPBR of approximately 125 yards, and its bullet is more frangible than the .22 LR bullet. The catalog energy is 88 ft. lbs. at 100 yards.

Better for short range varmint shooting is the .22 WMR (.22 Magnum). This more powerful rimfire cartridge extends the MPBR (+/- 1.5") for varmint hunting to about 125 yards, and its 40 grain jacketed hollow point bullets at a MV of 1910 fps are still packing 162 ft. lbs. of energy at 100 yards. The .22 WMR is far more deadly to varmints and small predators than the .22 LR or the .17 Mach 2. Its report is noticeably louder than that of the .22 LR or .17 Mach 2, but quieter than the .22 Hornet.

The best of all rimfire varmint cartridges is the .17 Hornady Magnum Rimfire (HMR). It is based on the .22 WMR case necked-down to accept .172" bullets. Its most popular load launches a 17 grain V-Max bullet at a MV of 2550 fps and ME of 245 ft. lbs. This cartridge has a MPBR (+/- 1.5") of about 165 yards when zeroed at 145 yards. At 150 yards it can still deliver 99 ft. lbs. of energy on target. Its factory loaded ammunition is brilliantly accurate, designed to shoot into 1 MOA or less. And its 17 grain V-Max bullet is fast and frangible enough to greatly reduce the possibility of ricochet.

The .17 HMR cartridge is also surprisingly quiet, probably due to its small diameter bore. It is probably the ideal varmint cartridge for use in semi-populated areas. A .17 HMR varmint rifle properly zeroed and equipped with a quality scope can take the smaller varmints at distances out to 200 yards. Recoil with all of the rimfire varmint cartridges is negligible.

Above the .17 HMR are the smallest centerfire varmint cartridges, such as the .22 Hornet and .218 Bee. These are .22 caliber cartridges, usually shooting a bullet weighing around 45 grains bullet at a MV of 2690-2760 fps and ME of 700-800 ft. lbs. Depending on the individual load, this class of cartridge offers a MPBR (+/- 1.5") of about 185-200 yards. Recoil in an 8.5 pound rifle is less than 1.5 ft. lbs. They are deadly varmint cartridges, and are usually about the most powerful cartridges recommended for use in semi-populated areas. The .22 Hornet was developed in the 1920's and introduced as a factory load in the early 1930's. It is the cartridge that really put long range varmint shooting on the map.

.223 Remington
Illustration courtesy of Hornady Mfg. Co.

The .221 Fireball, .222 Remington, .222 Rem. Mag., .223 Remington and similar cartridges represent the middle ground of varmint cartridges. These throw .224" jacketed varmint bullets usually weighing between 45 and 60 grains. MV's with 50 grain bullets run about 3000-3300 fps. ME is 1000-1200 ft. lbs. The MPBR (+/- 1.5") is around 215-235 yards, depending on the individual load.

Among these, the .222 Remington Magnum is obsolete, since neither rifles nor factory loaded ammunition are now offered, and the .221 Fireball has never really caught on. But the .222 and .223 Remingtons are very popular and versatile varmint cartridges. They are appropriate for use on the smallest to the largest varmints, and also on the small predators. Recoil is low, around 2.5 to 3 ft. lbs. in an 8.5 pound rifle, and accuracy is usually excellent. These are probably as near as we have to all-around varmint and small predator cartridges.

.22-250 Remington
Illustration courtesy of Hornady Mfg. Co.

Above the .222-.223 are what I refer to as the long range varmint cartridges. These range from .17 to .22 caliber. Among these are the .17 Remington (25 grain at 4040 fps), 204 Ruger (40 grain at 3900 fps), .225 Winchester (55 grains at 3570 fps), .224 Weatherby Magnum (55 grains at 3650 fps), .22-250 Remington (55 grains at 3680 fps), .220 Swift (50 grains at 3870 fps), and .223 WSSM (55 grains at 3850 fps).

The .22-250 and .220 Swift are the most popular of the long range varmint cartridges and have longest track records. The .22-250 is among the best selling of all varmint cartridges, second only to the .223 Rem. The .204 Ruger is the newest and fastest rising star among this class of cartridge. The .17 Remington and .223 WSSM have yet to excite much interest among main stream shooters, and the .225 Winchester and .224 Weatherby are no longer available in new rifles from their respective manufacturers, although factory loaded ammunition is still available. Both appear to be on their way out.

The .22-250 is representative of the small bore, high velocity varmint cartridges. Shooting a 55 grain Hornady SP bullet at a MV of 3600 fps it has a MPBR (+/- 1.5") of about 254 yards. The ME of that load is 1582 ft. lbs., and the 200 yard energy is 916 ft. lbs. The muzzle blast of a .22-250 is noticeably louder than that of a .223 Rem. Recoil is still low, typically about 4 ft. lbs. in an 8.5 pound rifle.

.243 Winchester
Illustration courtesy of Hornady Mfg. Co.

The last group of varmint cartridges are combination varmint/big game cartridges. These are usually high velocity .24 and .25 caliber cartridges, and at long range on windy days far from civilization they are perhaps the most effective varmint cartridges of all. Their heavier bullets of superior ballistic coefficient (BC) buck the wind better than .22 caliber varmint bullets. For comparison, the BC of a .22 caliber Hornady 55 grain Spire Point bullet is .235; the BC of a .24 caliber Hornady 80 grain Spire Point bullet is .283. The higher the BC number the better, and that is a significant difference.

Probably the best known of these cartridges are the .243 Winchester, 6mm Remington, .250 Savage, and .257 Roberts. Many modern shooters do not realize that the .243 and 6mm were developed as wildcat varmint cartridges. This was before they were adopted by Winchester and Remington and became dual purpose rounds.

The .243 Winchester is by far the most popular of the combination cartridges, and can be taken as reasonably typical. Factory .243 varmint loads launch an 80 grain bullet at a MV of 3350 fps with ME of 1993 ft. lbs. Such a load has a MPBR (+/- 1.5") of around 235-240 yards. Muzzle blast is not much worse than that of a .22-250 or .220 Swift, but recoil has about doubled, running between 7 and 8 ft. lbs. in an 8.5 lb. rifle.

.25-06 Remington
Illustration courtesy of Hornady Mfg. Co.

The .243 WSSM, .240 Weatherby Magnum, .25 WSSM, .25-06 Remington, and .257 Weatherby Magnum can achieve even higher velocities with varmint weight bullets. However, their muzzle blast and recoil, not to mention how quickly their barrels over heat, make them more suitable for hunting CXP2 class game than varmints. Big game hunters normally fire only one or two shots in an entire day; a varmint hunter in a good location may run through that many boxes of ammunition in a single day.

The .25-06 is the most popular of these calibers, and reasonably representative. As factory loaded it launches an 85 grain varmint bullet at a MV of 3470 fps and ME of 2273 ft. lbs. The MPBR (+/- 1.5") is about 255-260 yards. The muzzle blast is considerable, and very quickly grows tiring if much shooting is done. Recoil is up to around 9 ft. lbs. in an 8.5 pound rifle.

The big case .24 and .25 calibers are effective varmint cartridges, but overkill from my point of view. A .22-250 or .220 Swift can reach just as far and, although they are more susceptible to wind drift, they are a great deal more fun to shoot!

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Copyright 2006, 2010 by Chuck Hawks. All rights reserved.