The 7mm Remington Ultra Mag
By Chuck Hawks
The 7mm Remington Ultra Mag is the smallest of the Ultra Mag calibers. It offers ballistics roughly comparable to the 7mm STW, but burns more powder to do so. Because of its great case capacity it is overbore with all but the very slowest rifle powders. And because it burns so much powder and drives bullets at very high velocity, it also burns out barrels in short order. This has done nothing for the 7mm Ultra Mag's popularity.
Remington factory loads were initially offered with 140 and 160 grain bullets. Remington loaded two 140 grain bullets, a Core-Lokt PSP and a Nosler Partition spitzer. The 160 grain bullet was also a Nosler Partition spitzer. By 2004 however, due to lack of sales, this selection of factory loads had been reduced to a single offering, a 140 grain Core-Lokt Ultra at a MV of 3425 fps.
The handloader has a much greater choice of bullet weights. Those lighter than 139 grains would seem pointless in such a big case, but the 150 to 175 grain bullets have their purposes. A word of caution is appropriate here: there are reports of serious powder/pressure compatability problems with the 7mm Ultra Mag and some reloading companies do not include data for the cartridge in their manuals for that reason. This is one of few calibers that could be called risky to reload. It is certainly not for the novice reloader. Follow the data in your reloading manual exactly when reloading for the 7mm Ultra Mag and do not substitute components.
According to Hodgdon reloading data the 160 grain Nosler Partition bullet can be driven to a MV of 3214 fps. The trajectory of this bullet at a MV of 3200 fps looks like this: +2.4" at 100 yards, +3" at 150 yards, +2.5" at 200 yards, and -3" at 314 yards. This is probably the best all-around bullet weight for the caliber.
Hodgdon reloading data shows a maximum MV of 3093 fps with a Swift 175 grain bullet. This is not the best bullet weight for long range shooting, but for use on very heavy game where great penetration is desirable the 175 grain bullet's sectional density of .310 makes it a viable choice.
Note: A full length article about the 7mm Ultra Mag can be found on the Rifle Cartridge Page.
Copyright 2004 by Chuck Hawks. All rights reserved.