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 that I have found over the years to be quite useful for hunting:
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.
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 Remington, Ruger and Winchester brands and models are the most popular.
Remington - Model 700.
Ruger - M77.
Winchester - Model 70.
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.
I have owned more than a few 7mm Remington Magnum rifles over the years and most were extremely accurate, the first was a Winchester model 70 with 24", 1 in 9 1/2" twist barrel purchased in 1974, out of the box performance was 1 hole groups at 200 yards shooting factory remington 150 grain core-lokt bullets. Performance was well above board for that 7mm Remington Magnum rifle, several years later, after several thousand rounds, throat erosion was affecting its accuracy and I began experimenting with bullet, powder and primer combinations to regain its accuracy.
Using 160 grain speer flat based bullets, slightly lengthening the cartridge overall length, backed with a charge of IMR 4831 powder and ignited with a remington 9 1/2 large rifle primer (Not Magnum), superb accuracy returned.
(Accuracy: 1 hole, 5 shot groups at 200 yards).
Note: The above 7mm Remington Magnum load is extremely effective on elk, moose and bear and definately not recommended for deer hunting as the destruction on a deer shot with that loading and hit in the shoulder is very high.