Parent cartridge is the 7x61 Sharpe & Hart..later revised to the 7x61Super.
It predated the 7mm Remington Mag by almost 10 years.
My gunsmith is a huge fan of the cartridge.....I had Dave at PT&G make me a custom reamer for the 6.5 chambering.
Quickloads is showing 2,935 fps with a 139 gr. Lapua Scenar and 55.2 grs. of H4831SC with a chamber pressure of ONLY 46,822 psi......
...my chronograph will have to confirm!!
a MAXIMUM LOAD of 59.5 grs. shows 3,142 fps with a chamber pressure of 58,444 psi. BUT it is in between the OBT nodes....
Philip Sharpe and Richard Hart developed the 7x61mm in the early 1950's. In 1953 Schultz & Larson of Denmark started chambering their bolt action hunting rifle for a commercial version of the 7x61 S&H based on a shortened, blown out version of the .300 H&H Magnum case. Factory loaded ammunition was supplied by Norma of Sweden. The belted version of the 7x61 is also sometimes referred to as the 7mm S&H Super.
The 7x61's commercial popularity was limited by competition from the 7mm Weatherby Magnum, a more powerful standard length 7mm Magnum that was already on the ground. The introduction of the 7mm Remington Magnum in 1962 was the beginning of the end for the 7x61 in the U.S. market.
The commercial version of the 7x61 uses a belted magnum case 2.394" in length. Rim diameter is the standard magnum .532". Case length is 2.394" and overall cartridge length is 3.27". Bullet diameter is .284", the same as other true 7mm cartridges.
Norma supplied factory loaded ammunition for the 7x61 S&H. Their first offering was a 160 grain bullet at a muzzle velocity (MV) of 3100 fps with muzzle energy (ME) of 3410 ft. lbs. Later Norma introduced a 154 grain bullet at a MV of 3060 fps with ME of 3200 ft. lbs.
Handloaders can essentially duplicate the Norma factory loads, and have access to bullets of lighter and heavier weight. The fifth edition of the Hornady Handbook of Cartridge Reloading shows 7x61 S&H loads for their 139, 154, 162, and 175 grain bullets. As with other 7mm Magnum cartridges, slow burning rifle powders work best in the 7x61.
According to the Hornady Handbook their 139 grain SST boat-tail spitzer bullet can be driven to a MV of 2800 fps by 57.8 grains of H4831 powder, and a MV of 3200 fps by a maximum load of 65.0 grains of H4831. The trajectory of that bullet at a MV of 3100 fps looks like this: +2.5" at 100 yards, +2.3" at 200 yards, -2.5" at 300 yards, and -6.9" at 350 yards. The maximum point blank range (+/- 3") is 305 yards.
The Hornady Handbook shows that their 175 grain Spire Point Interlock bullet can be driven to a MV of 2500 fps by 53.9 grains of H4831 powder, and a MV of 2900 fps by a maximum load of 62.5 grains of H4831. The latter load has a ME of 3267 ft. lbs., and at 200 yards the numbers are 2507 fps and 2441 ft. lbs. The trajectory of that load looks like this: +2.6" at 100 yards, +1.9" at 200 yards, and -4.1" at 300 yards. The maximum point blank range (+/- 3") is 287 yards.
The 7x61 Sharpe & Hart never became very popular in the U.S. However, it has always gotten favorable mention in the firearms press, and remains a potent long range hunting cartridge.