Scope Magnification and Rifle Caliber By Chuck Hawks The whole point to this little missive is to help less experienced shooters choose a riflescope that is appropriate for the caliber and purpose of their rifle. In other articles on Guns and Shooting Online we have recommended specific scopes by price class and brand name, but this is a more general treatment. This article should steer the reader in the direction of the correct magnification of either a fixed power scope or an appropriate magnification range of a variable power scope for their hunting rifle. For each category there are examples of suitable calibers. These brief caliber lists are not intended to be allinclusive, so if your caliber is not listed, find something similar and there is your recommended scope. For example, if your rifle is a .250 Savage (which is not listed below), you can reasonably use the scopes recommended for the .257 Roberts. Scopes for rimfire small game cartridges These cartridges are used for hunting small animals such as squirrels and rabbits (CXP1 game), at fairly short range (less than 100 yards). The cartridges in this class include the .17 M2, .17 HMR, 5mm Rem, .22 LR, .22 WRF, and .22 WMR Fixed power scopes  Minimum magnification 3x; Maximum magnification 6x; 4x scope recommended. Variable power scopes  Minimum magnification 2x to 3x; maximum magnification 7x to 9x; 39x (approximate) scope recommended. Scopes for short to medium range varmint cartridges Examples of such cartridges are the .17 HMR, .218 Bee, .22 WMR, .22 Hornet, .256 Win. Mag. and cartridges with similar trajectories. These rimfire and small centerfire cartridges are useful for shooting varmints such as groundhogs and prairie dogs (CXP1 game) at maximum ranges between about 125 and 200 yards, depending on the specific caliber. An adjustable objective (AO) or side focus scope adjustable for parallax is recommended. Fixed power scopes  Minimum magnification 6x; maximum magnification 10; 8x scope recommended. Variable power scopes  Minimum magnification 3x to 6x; maximum magnification 10x to 15x; 412x (approximate) scope recommended. Scopes for medium to long range varmint cartridges These flat shooting, centerfire varmint and small predator (CXP1 game) cartridges can often get by with the scopes recommended in the category above, but sometimes they can use more magnification. Typical maximum ranges run 225300 yards. Common examples of such varmint cartridges include the .17 Rem, .204 Ruger, .222 Rem, .223 Rem, .22250, .220 Swift, .243 Win., 6mm Rem. and similar cartridges. An adjustable objective (AO) or side focus scope adjustable for parallax is recommended. Fixed power scopes  Minimum magnification 6x; maximum magnification 12x; 10x scope recommended. Variable power scopes  Minimum magnification 4x to 8x; maximum magnification 12x to 25x; 618x (approximate) scope recommended. Scopes for short range big game cartridges These are short range (MPBR +/ 3" typically 150175 yards or less) CXP2 and CXP3 class game cartridges. Examples include the .357 Mag., .3855, .4440, .44 Rem. Mag., .45 Colt, .4570, and cartridges with similar trajectories. These are often thought of as woods and brush calibers, where a wide field of view is usually more important than high magnification. Fixed power scopes  Minimum magnification 2x; maximum magnification 4x; 2.5x scope recommended. Variable power scopes  Minimum magnification 1x to 2.5x; maximum magnification 3x to 7x; 14x (approximate) scope recommended. Scopes for medium range big game cartridges These are CXP2 and CXP3 class game cartridges with a MPBR +/ 3" typically between 200250 yards. Examples of such cartridges include the .2535, 730 Waters, 7.62x39, .3030, .307 Win., .32 Spec., .358 Win., .35 Whelen, .350 Rem. Mag., 9.3x62, 9.3x74R, and cartridges with similar trajectories. Appropriate scopes need a wide field of view as well as enough magnification to allow shots across ravines and clear cuts. Fixed power scopes  Minimum magnification 2x; maximum magnification 4x; 3x scope recommended. Variable power scopes  Minimum magnification 1.5x to 2.5x; maximum magnification 4x to 8x; 27x (approximate) scope recommended. Scopes for "all around" and long range big game cartridges These are CXP2 and CXP3 class game cartridges with a MPBR +/ 3" typically between 250300+ yards. Included in this category are most of the "allaround" big game cartridges. Examples include the .243 Win., 6mm Rem., 6mm Magnums, .257 Roberts, .2506, .25 Magnums, .260 Rem., 6.5x55, 6.5mm Magnums, .270 Win., .270 Magnums, 7mm08, 7x57, .280 Rem., 7mm Magnums, .308 Win., .3006, .300 Magnums, 8x57JS, 8mm Magnums, .33806, .338 Magnums and cartridges with similar trajectories. Appropriate scopes offer a reasonable field of view at low power and enough magnification for long range shots at big game animals when they cannot be avoided. Fixed power scopes  Minimum magnification 4x; maximum magnification 6x; 4x scope recommended. Variable power scopes  Minimum magnification 2x to 3.5x; maximum magnification 8x to 10x; 39x (approximate) scope recommended. Scopes for dangerous game cartridges These are CXP3 and CXP4 class game cartridges intended for hunting large predators (the great bears and big cats), bovines, rhino, and elephant. Examples of suitable cartridges include the .33806, .338 Magnums, .35 Whelen, .35 Magnums, 9.3x62, .375 Magnums, .405 Winchester, .416 Rigby, .416 Magnums, .450 Marlin, .458 Win. Mag., .460 Wby. Mag, .470 NE and similar cartridges. It is generally recommended to shoot dangerous game at ranges between 50 and 150 yards whenever possible, so high magnification scopes are not necessary. What is necessary is a very wide field of view and long eye relief. Fixed power scopes  Minimum magnification 1x; maximum magnification 2.5x; 2.5x scope recommended. Variable power scopes  Minimum magnification 1x to 2x; maximum magnification 3x to 5x; 14x (approximate) scope recommended. 
Copyright 2007, 2013 by Chuck Hawks. All rights reserved.
