The 7x57 Mauser (.275 Rigby)

Americans discovered the 7mm Mauser (7x57) in Cuba during the Spanish-American War, where they were dismayed by it's high velocity, flat trajectory, and the superior (compared to the American .30-40 Krag rifle) Mauser rifle for which it was chambered. That bitter experience spurred the development of our own Mauser pattern service rifle, the 1903 Springfield, and the legendary .30-06 cartridge (which is an enlarged 7x57).

The 7x57 was developed by the famous German firm of Mauser in 1892, and adopted by the Spanish government in 1893. Subsequently, several Latin American countries adopted the 7x57, including Mexico. In Europe, Serbia adopted the cartridge, and it became a popular sporting cartridge all over Europe. In Great Britain the 7x57 became so popular that the John Rigby Company adopted it as the .275 Rigby. Many bolt action rifles built in the UK were so marked. Under both names the cartridge was used extensively for plains and mountain game in Africa and Asia. Ammunition is manufactured and sold in Europe, Africa, North America and most of the world. The 7x57 is a true world-wide cartridge.

In the U.S., the 7x57 has a small but devoted following that has kept it alive all these years. Colonel Townsend Whelen, celebrated gun writer in the earlier years of the 20th century, was a fan of the 7mm Mauser and wrote eloquently about it.

Eleanor O'Connor, wife of Jack O'Connor, used the 7x57 extensively and killed just about everything non-dangerous in North America and Africa with it. She was an excellent shot, and liked the 7x57 because it didn't kick as hard as a .270 or .30-06, but seemed to kill just as well.

Jack O'Conner also used and praised the 7x57, for which he had a lot of respect. He wrote that he had killed 10 head of game animals with 11 shots, all using the Western 139 grain spitzer bullet at a muzzle velocity of about 2,800 fps. He described that load thusly: "That load was a vicious killer--and I don't mean maybe--a one shot killer on mule deer, sheep and antelope." He also wrote that the 7x57 was about the lightest cartridge that he considered as satisfactory for all-around use, and that the 7x57 would do just about anything that the .30-06 would do and that the recoil was much less.

W.D.M. Bell, perhaps the most famous of all African commercial ivory hunters, killed the majority of his over 1000 elephants with the 7x57. He used the 175 grain FMJ bullet for brain shots, and liked the .275 Rigby (as he called the 7x57) for its accuracy and low recoil and report.

The recoil energy for an 8 pound rifle firing a 140 grain bullet at 2,800 fps is about 14 ft. lbs. Contemporary American factory loads for the 7x57 are held to less than 46,000 cup. For rifles with strong actions, like all modern bolt actions, the 7x57 can be safely handloaded to higher pressures of around 50,000 cup, and consequently better performance.

There is a wide variety of .284 bullets available to the reloader, from around 110 grains to 175 grains. Barnes offers a 175 grain RN solid (SD .310) and a 195 grain soft point spitzer bullet (SD .345). The North American shooter who wants to get maximum utility out of a 7x57 really should be a reloader.

Current ammunition catalogs from PMC, Remington and Federal show loads for the 7x57 with 140 grain spitzer bullets (SD .248) at a muzzle velocity (MV) of 2,660 fps and muzzle energy (ME) of 2,199 ft. lbs. Winchester loads a 145 grain spitzer to the same MV for a ME of 2279 ft. lbs. Federal and PMC also load 175 grain RN bullets at a MV of 2440 fps and ME of 2315 ft. lbs. These are the standard American low pressure factory loads.

Hornady offers a standard pressure load with a 139 grain bullet at 2,700 fps--evidently Hornady loads a bit closer to the maximum. Hornady also offers two hotter loads in their "Light Magnum" line: a 139 grain boat tail spire point bullet (BC .485, SD .246) at a MV of 2,830 fps and a ME of 2,475 ft. lbs., and a 139 grain flat base spire point (BC .396, SD .246) at a MV of 2,950 fps and a ME of 2,686 ft. lbs. The trajectory of the former load looks like this (Federal figures): +2.0" at 100 yards, 0 at 200 yards, -7.6" at 300 yards. This is also typical of the performance of the best handloads.

In Europe, Sako factory loads include a 170 grain spitzer bullet at a MV of 2,495 fps and a ME of 2,324 ft. lbs. Norma loads a 150 grain soft point bullet at a MV of 2690 fps with ME of 2411 ft. lbs. The ballistics of all 7x57 factory loads are taken in 24 inch test barrels.

The reloader who loads to about 50,000 cup can do better. According to the Speer No. 13 Reloading Manual the Speer 130 grain spitzer bullet (BC .394, SD .230) can be driven to 2649 fps by 46.0 grains of H414 powder, and 2960 fps by 50.0 grains of H414. The 145 grain Spitzer (BC .457, SD .257) can be driven to 2501 fps by 44.0 grains of H414, and 2748 fps by 48.0 grains of H414. The 160 grain spitzer (BC .502, SD .284) can be driven to 2,363 fps by 42.0 grains of H414, and 2582 fps by 46.0 grains of the same powder. All of the above loads used Remington cases and CCI 250 primers, and were chronographed in a 22 inch barrel.

Generally, the 120-140 grain bullets are recommended for deer and antelope size game, while the 160-175 grain bullets are recommended for bigger game like elk and moose. Something in the 139-150 grain range would probably make a pretty good general purpose load in the 7x57. Such a load can be zeroed for 200 yards, at which range it delivers around 1,800-2,000 ft. lbs. of energy.

My Rifle Trajectory Table shows that the trajectory of a 145 grain Speer boat-tail spitzer bullet at a MV of 2790 fps looks like this: +2.7" at 100 yards, +1.8" at 200 yards, and -5" at 300 yards. This makes the 7x57 a 279 yard cartridge (+/- 3"), just like the 7mm-08 Rem. In fact, the practical performance of the two cartridges is almost identical, because although the 7.57 has a little more case capacity, the 7mm-08 is normally loaded to higher pressure.

One last observation about the 7x57: although it is a compact cartridge, it is a little longer than modern "short action" cartridges like the .243, 7mm-08, and .308. The modern short action cartridges developed from the .308 case have a maximum overall length of about 2.8 inches. The 7x57's maximum overall length is 3.065 inches. Mauser made a special intermediate length action for the 7x57. Today, Ruger chambers the 7x57 in their standard length action, not the short action. This means that bolt action rifles for the ballistically similar 7mm-08 can be a bit more compact than those for the 7x57. The flip side is that the 7x57 handles bullets over 140 grains better than the 7mm-08. The relatively long 150+ grain bullets can be seated normally and do not intrude into the powder space of the 7x57 case.