7mm Remington Magnum Rifles & Accuracy:
Remington chambered the 7mm Remington Magnum cartridge in their Model 700 bolt action rifle in 1962 and it featured a 1 in 9" rifling twist. The 7mm Remington Magnum has been chambered by most major high power rifle manufacturers for quite some time and they have offered these rifles with rifling twist rates from 1 in 9" - 1 in 10". Because of the velocity range, quirky nature of .284 diameter bullets in that velocity range, the 7mm Remington Magnum concerning bullet performance with various twist rates by various rifle manufacturers mixed performance results can be quite substantial, here is a barrel and bullet guide:
1 in 9" Twist Rate: 160 - 175 grain bullets, minimum barrel length 26 inches for maximum performance on large game such as moose and big bears.
1 in 9 1/2" Twist Rate: 140 - 160 grain bullets, minimum barrel length 24 inches for maximum performance on big game such as antelope, deer, elk and moose.
1 in 10" Twist Rate: 115 - 140 grain bullets, minimum barrel length 24 inches for maximum performance on varmints, predators, antelope, deer and elk.
Note: How To Measure Rifling Twist Rate.
Rifle barrel length is very important to bullet speed for the 7mm Remington magnum which affects bullet energy and trajectory.
20 to 26 Inch Rifle Barrel Lengths Velocity Adjustment:
Rifle Barrel Length Shorter Than 24 Inch You Subtract Velocity.
Rifle Barrel Length Longer Than 24 Inch You Add Velocity.
2,500 to 3,000 feet per second advertised velocity, adjust at 20 feet per second per inch from standard of 24 inch rifle barrel.
3,000 to 3,500 feet per second advertised velocity, adjust at 30 feet per second per inch from standard of 24 inch rifle barrel.
When choosing a rifle cartridge you should always evaluate what you are going to use the rifle for and then select the rifle with the correct rifling twist rate for your imparticular use by bullet weight to gain the most accuracy and bullet expansion.
A good rule of thumb is that the heavier and longer a bullet is, the faster the rifling twist rate needs to be to stabilize it in flight, therefore a lighter shorter bullet needs a slower rifling twist rate to give proper bullet spin for correct flight and expansion.
The Bolt Action is the most popular rifle action type used in North America chambered in the 7mm Remington Magnum cartridge, of which the Remington Model 700, Ruger M77 and Winchester Model 70 brands and models are the most popular.
To achieve the maximum accuracy from your 7mm Remington Magnum rifle there are several things you need to do correctly and this applies to new and used rifles.
1. Properly mount your rifle scope.
2. Properly break-in your rifle barrel.
3. Properly sight-in your rifle with this free accurate sight-in target.