7x61 Sharpe and Hart Super
Date: May 30 2014
Notes from the Lab: 7x61 Sharpe and Hart Super
The 7x61 Sharpe and Hart Super was developed by Phillip B. Sharpe and Richard Hart around 1953. The case was essentially a .300 H&H Magnum shortened to 2.394 inches, its shoulder was blown out and necked to accept .284/7mm bullets. With a maximum overall cartridge length of 3.270 inches, it could be housed in any .30-06-length action. Norma of Sweden began offering factory ammunition and added "Super" to the name. Early factory ballistics pushed a 160-grain bullet to around 3,100 fps, with 139- and 175-grain loads being added later (now discontinued.). Currently, a 154-grain factory load is offered at an advertised 3,060 fps. Schultz and Larsen (Denmark) offered bolt-action rifles including the Models 60, 65 and 68 DL, and many custom guns have been built on a variety of actions.
The 7x61 S&H is an excellent choice for hunting deer, elk and pronghorn in open country, and when stoked with premium bullets it is suitable for moose, the great bears and African plains game. As such, it gained some degree of popularity worldwide, but when the 7mm Remington Magnum appeared in 1963, its popularity began to decline.
Although the 7x61 S&H was based on the .300 H&H Magnum case, for unknown reasons there are slight dimensional differences with the rim, extractor slot and belt. To complicate matters, these dimensions are not identical with all Norma ammunition. For example, to prepare this data, several different lot numbers of cases (and ammunition) from different eras were purchased from several sources. Some batches worked correctly in the standard .300 H&H Magnum belted case shell holder (RCBS No. 4) while many cases would not fit. Shell holders from Hornady, Redding, Lyman and Lee were also tried, but cases still would not insert properly in any of them. The problem area was usually with the cases’ shallow-cut extractor groove. This required a lathe cut alteration to the shell holder to get all cases to work. If a lathe is not readily available it is suggested to send a couple of sample cases to a shell holder manufacturer, and let them make the necessary alteration.
Using the 154-grain Hornady SP bullet, IMR-4320 and IMR-4350 duplicated or exceeded current factory load velocities, with the latter being the most accurate powder tried with both 154- and 162-grain bullets. Switching to 175-grain bullets, Hodgdon H-4831 gave the best overall performance.
Although the 7x61 S&H is a magnum, Federal 210 Large Rifle (non-magnum) primers were used to develop loads, which gave satisfactory ignition. If a magnum primer is used, maximum charges will need to be reduced.