format_quoteIntroduced in 2001, Winchester intended the 7mm Winchester Short Magnum (WSM) to approximate performance of the 7mm Remington Magnum in a shorter action. It comes close to achieving this goal.
Because it uses less propellant and because less of that is accelerated down the bore before it burns, all else being equal, this shorter case generates less felt recoil and is more efficient in converting propellant into bullet velocity, as opposed to recoil, muzzle blast, barrel heating, and bore damage.
As progressively heavier and longer bullets become available, the 7mm WSM has progressively more to offer, especially when chambered in a long-action rifle where the handloader can seat the bullets out to take advantage of what the magazine will handle.
This is not possible with the conventional 7mm Magnums unless those are chambered in guns that will handle the original full-length magnums, which are somewhat awkward for some shooters to use — the long bolt stroke is problematic for many shooters when trying to work the action with the rifle shouldered.
In a long-action, where the bullet can be seated out so it does not infringe the case body significantly, the 7mm WSM rifle can shoot the high-BC Berger bullets up to 195 grains with striking results. This combination offers impressive long-range performance.
As with so many modern cartridge designs, the one negative aspect is the too-short case neck. Had Winchester merely driven the shoulder back about 0.1-inch, barrel life would be doubled for a velocity loss of 10-fps or less! No target would ever know the difference in velocity but the gun owner who shoots a lot might well learn it. I am reminded of a lifelong friend who wore out the barrel in his 7mm Rem Mag with about 35 years of perfectly normal use involving only initial load development work, checking his zero each year, and hunting once a year, along with some varmint hunting. On a lark, he chronographed the load again. He was shocked to discover velocity of his 175-grain load was down 300 fps from what it had been, making it just a bit slower than 30-06 factory 180-grain loads! He figures he put no more than 1000 rounds through that barrel, he did take care of it, and he was careful to avoid overheating it.
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