"The critical importance of the wildcatter is perhaps no better illustrated than in the development of modern 6mm cartridges. Following WWII, American experimenters began working with this essentially European caliber. (The 6mm Lee Navy cartridge, the only American development in the field, enjoyed rather limited acceptance between its introduction in 1895 and 1935, the year factory loading of it was discontinued.) Their work sparked commenrcial interest in the caliber.
The .243 Winchester is a 6mm cartridge necked down from the .308 Winchester, sporting version of the 7.62 NATO round. Warren Page, Shooting Editor of FIELD & STREAM, developed an important prototype of this cartridge, and Winchester brought out its design in 1955. It became an immediate success as a dual purpose varmint/medium game cartridge." (Hornady Handbook of Cartridge Reloading, 1967)
The .243 Winchester shares the same parent case as the .308 Winchester and 7mm-08 Remington. The most common .243 caliber big game hunting bullet weight is 100 grains. Few might consider a premium bullet in 85 grains capable of killing game species such as antelope and deer. The .243 in general is a very capable hunting caliber, although many would argue that it on the light side caliber-wise. That being said, numerous elk have fallen to the fast and flat shooting .243, and my grandfather personally killed a cow moose many years ago with a strategically placed bullet from his sharp shooting .243 Winchester.
For the sake of this discussion we will compare the 85, 90, and 100 grain bullets which are most commonly found in off the shelf ammunition. Since I mentioned above that the 85gr bullet may be considered in a premium bullet, let’s take the Nosler Partition bullet and make up a load using the same powder (IMR 4831) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 85gr Nosler Partition; BC = 0.315; Velocity = 3233fps
- 90gr Nosler Partition; BC = 0.365; Velocity = 3050fps
- 100gr Nosler Partition; BC = 0.384; Velocity = 2947fps
"The 25-06 is a wildcat simply derived by necking down a 30-06 case to 25 caliber. A.O. Niedner introduced rifles in this caliber in 1920, naming them the 25 Niedner, and retaining the 17° 30’ shoulder of the parent cartridge. (Many gunsmiths use the 270 case as the basis of the 25-06 and in so doing gain the advantage of a slightly longer neck.) A popular wildcat which has gained favor in the past decade [1960’s], the 25-06 has a good reputation for varmints and medium sized game.” (Hornady Handbook of Cartridge Reloading, 1967)
The .25-06 shares the same parent case as the .30-06 Springfield and .270 Winchester. Common .257 caliber big game hunting bullet weights range from 80 to 120 grains.
For the sake of this discussion we will compare the 90, 100, and 117 grain bullets which are commonly found in off the shelf ammunition. Let’s take the Sierra GameKing bullet and make up a load using the same powder (IMR 4350) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 90gr Hornady SST; BC = 0.250; Velocity = 3348fps
- 100gr Hornady SST; BC = 0.355; Velocity = 3257fps
- 117gr Hornady SST; BC = 0.410; Velocity = 3106fps
“The 6.5x55 is an excellent and deservedly popular military surplus import. Adopted as the Swedish service cartridge in 1894 and chambered in three different Mauser rifle models, the cartridge is today widely popular in Sweden and Norway (where it was used in Krag-Jorgensen rifles) and it continues to gain boosters in this country.
The 6.5x55 differs from the rest of the Mauserwerke’s smokeless powder military cartridges in not sharing the same basic case; its head diameter is 0.015” larger and its rim somewhat thicker.
Loaded with a 130 or 140 grain bullet, the 6.5x55 is acceptable for all but the largest North American game. Reloaders are cautioned, however, against attempting really high intensity loads in either the Mauser or Krag actions for these were not designed for pressures commonly developed in current factory rifles.” (Hornady Handbook of Cartridge Reloading, 1967)
Common .264 caliber (6.5mm) big game hunting bullet weights range from 100 to 160 grains. For the sake of this discussion we will compare the 100, 120, and 140 grain bullets which are commonly found in off the shelf ammunition. Let’s take the Nosler Ballistic Tip Hunting bullet and make up a load using the same powder (IMR 4831) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 100gr Nosler Ballistic Tip Hunting; BC = 0.350; Velocity = 3177fps
- 120gr Nosler Ballistic Tip Hunting; BC = 0.458; Velocity = 2812fps
- 140gr Nosler Ballistic Tip Hunting; BC = 0.509; Velocity = 2528fps
The 7mm-08 Remington shares the same parent case as the .308 Winchester and .243 Winchester. Common .284 caliber (7mm) big game hunting bullet weights for the 7mm-08 range from 100 to 175 grains. Other bullet weights are available on the lighter end of the weight spectrum and could be considered for the light skinned game such as antelope. The .284 caliber 7mm-08 in general is a very capable hunting caliber and is widely considered the optimized caliber for the case dimensions exceeding the .243 Win is energies due to heavier bullets being widely available and exceeding the velocities achieved in the .308 Win platform. This combination of superior energy and velocity makes it a lethal combination. Adding to that, recoil is very manageable so this makes the 7mm-08 a perfect cartridge for recoil shy and/or young hunters. My first several years of rifle deer hunting found me toting my grandfather’s 7mm-08, I have fond memories of this cartridge.
For the sake of this discussion we will compare the 139, 154, and 162 grain bullets which are commonly found in off the shelf ammunition. Let’s take the Hornady SST bullet and make up a load using the same powder (Winchester 760) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 139gr Hornady SST; BC = 0.486; Velocity = 2810fps
- 154gr Hornady SST; BC = 0.525; Velocity = 2731fps
- 162gr Hornady SST; BC = 0.550; Velocity = 2632fps
“Spurred by Winchester’s success with its 264 magnum, Remington introduced a competitive answer in 1962 when it brought out its 7mm magnum. The Remington development seems destined for even greater popularity than its rival 6.5mm magnum, though the two cartridges are quite similar in size, power, and performance.
The 7mm Remington Magnum features a belted head, power enough for anything on this continent, a flat trajectory, good loading versatility because of the wide range of bullets available for it.” (Hornady Handbook of Cartridge Reloading, 1967)
Cartridge dimensions are nearly identical to the .300 Win Mag and .338 Win Mag, simply necked down to receive a .284 caliber bullet. Common .284 caliber (7mm) big game hunting bullet weights range from 100 to 180 grains. Bullets that are towards the heavier end have exceptionally high ballistics coefficients which result in very flat trajectories for these heavier projectiles. That makes this cartridge a popular choice for long range hunters.
For the sake of this discussion we will compare the 140, 150, 160, and 175 grain bullets which are commonly found in off the shelf ammunition. Let’s take the Nosler Partition bullet and make up a load using the same powder (IMR 4831) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 140gr Nosler Partition; BC = 0.434; Velocity = 3053fps
- 150gr Nosler Partition; BC = 0.456; Velocity = 2925fps
- 160gr Nosler Partition; BC = 0.475; Velocity = 2858fps
- 175gr Nosler Partition; BC = 0.519; Velocity = 2710fps
“The 270 Winchester is second in popularity as an all-around big game cartridge only to the venerable .30-06 Springfield. Introduced by Winchester in 1925 in the firm’s Model 54 bolt action rifle, the 270 is currently chambered in a wide variety of U.S. and European rifles.
An effective performer on all North American game and a wide variety of thin skinned African game, the 270 combines good killing power with flat trajectory to maintain its outstanding reputation.” (Hornady Handbook of Cartridge Reloading, 1967)
The .270 Winchester is a .30-06 case necked down to .277 caliber. Common .277 caliber big game hunting bullets weights for the .270 Winchester include 120, 130, 140, and 150. Few bullet manufacturers offer a light for caliber 100 and 120 grain bullet while others offer a heavy for caliber 160 grain bullet. This is one of the benefits of the .270 Win, there is a wide range of useful hunting bullets and loads can be tailored to the game being pursued.
For the sake of this discussion we will compare the 130, 140, and 150 grain bullets which are most commonly found in off the shelf ammunition. Let’s take the Nosler Ballistic Tip Hunting bullet and make up a load using the same powder (IMR 4350) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 130gr Ballistic Tip Hunting; BC = 0.370; Velocity = 3028fps
- 140gr Ballistic Tip Hunting; BC = 0.456; Velocity = 2916fps
- 150gr Ballistic Tip Hunting; BC = 0.496; Velocity = 2809fps
“Versatile, flexible, adaptable, above all popular, the 30-06 is the most widely used big game cartridge in America today. Among the most powerful military cartridges ever adopted, the 30-06 became the U.S. Army service cartridge in 1906 (hence the “06”), saw the nation through two World Wars and Korea, and began its rapid ascent to present sporting popularity following WWII.
Because of a very wide range of bullets and styles available in the .30 caliber – 100, 110, 130, 150, 165, 170, 180, 200, and 220 grain – 30-06 loads can be tailored for virtually every hunting requirement on the continent. It does not have the long range potential of many modern magnums in 6.5mm, 7mm, 30, and 338 calibers, nor does it have the flat trajectories and faster velocities of smaller caliber varmint cartridges; but to 300 yards it does quite well in both departments.” (Hornady Handbook of Cartridge Reloading, 1967)
Common .308 caliber big game hunting bullets weights for the .30-06 Springfield include 150, 165, and 180 grains. A few of the bullets are offered in light for caliber 130 grain bullet and there are a good number of heavy for caliber 200 grain options as well. I will include the 200 grain option in this discussion just to provide the full spectrum of data even though this bullet weight is not commonly used or seen in off the shelf ammunition.
Let’s take the Sierra GameKing bullet and make up a load using the same powder (Winchester 760) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 150gr Sierra GameKing SBT; BC = 0.380; Velocity = 2992fps
- 165gr Sierra GameKing SBT; BC = 0.404; Velocity = 2877fps
- 180gr Sierra GameKing SBT; BC = 0.501; Velocity = 2743fps
- 200gr Sierra Gameking SBT; BC = 0.560; Velocity = 2579fps
“Had Winchester quickly produced a 30 caliber magnum in its 458/338/264 magnum series, it could have brought out the same cartridge known as the 30/338 among wildcatters. But Norma pre-empted this development with its 308 Norma Magnum, and to enter the growing 30 caliber magnum market which was increasingly disinterested in the firm’s 300 H&H offerings, Winchester introduced the new 30 caliber magnum design in 1963.
In the 300 Winchester Magnum the 338 magnum’s shoulder was moved forward 0.516” and the case lengthened by 0.120”, leaving a very short neck of less than 1 caliber. With bullets seated quite deeply, the new Winchester round would still work through standard length bolt actions, and hold a bit more powder than the 308 Norma Magnum. All the components made for loading the 30 caliber Norma Magnum apply to the 300 Winchester Magnum.
The popularity of this Winchester cartridge has increased significantly since its introduction. Slightly less powerful than the older 300 Weatherby Magnum, the 300 Winchester Magnum’s future growth can only be aided by the wide number of arms chambered for it and the ready availability of factory ammunition.” (Hornady Handbook of Cartridge Reloading)
Common .308 caliber big game hunting bullets weights for the .300 Winchester Magnum include 150, 165, and 180 grains. A few of the bullets are offered in light for caliber 130 grain bullet and there are a good number of heavy for caliber 200 grain options as well. I will include the 200 grain option in this discussion because in the .300WM platform the 200 grain bullet is definitely a viable hunting option.
Let’s take the Sierra GameKing bullet and make up a load using the same powder (Hodgdon H4831) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 150gr Sierra GameKing SBT; BC = 0.380; Velocity = 3207fps
- 165gr Sierra GameKing SBT; BC = 0.404; Velocity = 3142fps
- 180gr Sierra GameKing SBT; BC = 0.501; Velocity = 3025fps
- 200gr Sierra Gameking SBT; BC = 0.560; Velocity = 2825fps
“The 338 Winchester Magnum has power to spare on elk and moose; a superbly flat trajectory with fine killing power for long range shots on sheep; dependable deadliness on the largest North American bear; and the right combination of velocity and energy for hunting the largest varieties of African plains game. One of the series of Winchester magnums based on the belted 458 magnum case, the 338 was introduced in 1958 and has since gained considerable following, though it’s somewhat more powerful than necessary for most American hunting. The cartridge owes much to Elmer Keith and his years of promotion for his wildcat 333 OKH.
Less powerful than the 375 H&H at the muzzle (though more potent at 100 yards with an efficient 225 grain bullet), the 338 Winchester will work through standard length bolt actions like the Model 70 and has been chambered by several other rifle makers as well.” (Hornady Handbook of Cartridge Reloading)
The .338 Winchester Magnum, in the opinion of many, is the king of the magnum cartridges. There are a handful larger, but the .338 Win Mag seems to have the widest distribution. It shares the same parent case as the 7mm Remington Magnum and very similar case dimensions as the .300 Winchester Magnum. Common .338 caliber big game hunting bullet weights range from 160 to 300 grains. While unable to generate the velocities of the 7mm Rem Mag or the .300 Win Mag, it more than makes up for it in energy generated. .338 caliber bullets carry a high sectional density and moderate ballistics coefficients resulting in energies that are more than sufficient to kill any big game species found not only in the western US but nearly any game worldwide.
For the sake of this discussion we will compare the 210, 225, and 250 grain bullets which are commonly found in off the shelf ammunition. Let’s take the Nosler Partition bullet and make up a load using the same powder (H4831) at the max load for each bullet weight according to the online Hodgdon reloading database and use a ballistics calculator (Strelok+ App) to compare their respective trajectory, energy, and wind deflection using the following inputs:
- 210gr Nosler Partition; BC = 0.400; Velocity = 2888fps
- 225gr Nosler Partition; BC = 0.454; Velocity = 2792fps
- 250gr Nosler Partition; BC = 0.473; Velocity = 2655fps
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