Bolt thrust generated by a standard, .473 in (12.0 mm) diameter case head operating at 80,000 psi (550,000 kPa) is equivalent to a .532 in (13.51 mm) case head operating at 64,000 psi (441,000 kPa). Accordingly, any rifle action compatible with existing magnum cartridges, such as the .300 PRC, is also compatible with the 7mm Backcountry. Additionally, due to differences in the mechanics of shear transfer, the steel case of the 7mm Backcountry imparts less bolt thrust than an equivalent high-pressure brass case.[5]
Performance
Federal claims that the 7mm Backcountry is "the fastest 7mm [cartridge] on the market."[6] Early reports indicate that it approximates the performance of a 24-inch 7mm Remington Magnum with a 16-inch barrel.[7]
According to early coverage by outdoor writer John Snow, the 7mm Backcountry uses propellant(s) presently unavailable for handloading,[11] though Federal has now published load data using Alliant, Hodgdon, Ramshot, and Vihtavuorismokeless powders.[12] These loads match the velocity claims of Federal’s factory ammunition when figures from equivalent barrel lengths are compared, and Federal describes the data as "...high-pressure loads for Peak Alloy cases only."[6][12]
To guard against corrosion, Federal does not recommend reloading cases with a zinc-nickel-plated exterior; for this purpose, nickel-plated cases are preferred.[13] Trimming, deburring, and some cleaning procedures commonly used in handloading brass cases may damage the nickel-plated steel case; and wax lubricants are recommended to minimize resizing effort. Lightly flaring the case mouth is advisable to avoid damaging the bullet during seating.[14]
Suppressors
The 7mm Backcountry produces relatively intense muzzle blast from short barrels, which encourages the use of suppressors. According to Federal engineers, "...despite the high pressures the round develops in the chamber, the pressure at the muzzle is no greater than a regular 7mm magnum round, like the 7mm PRC."[11] Accordingly, where laws permit, the same suppressors may be used.
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