RIFLES
Multitask Magnum
The .270 WSM offers plenty of options, making it our resident big-game expert's favorite .277 cartridge.
|
|
At this writing there are five new "short magnums"--fat-cased, rebated-rim cartridges designed to fit actions that will more or less house the smaller-diameter .308 Winchester family of cartridges. All are good, although their popularity certainly isn't equal. To my thinking, the .270 Winchester Short Magnum is the most interesting because I see it as offering a level of performance that has not been readily available. The 60-year-old .270 Wby. Mag. is a slightly faster and truly excellent cartridge. But it has remained primarily a Weatherby exclusive, and its availability is limited.
Part of the interest in the .270 WSM is based on the fact that there are now only three commercial cartridges using the .277-inch bore diameter. Unlike the many 7mm and .30-caliber cartridges, the .270 field has long been limited to just the .270 Winchester and the .270 Wby. Mag. Thus it wasn't exceedingly difficult for the .270 WSM to find a distinctive niche. It is significantly faster than the .270 Winchester and can be chambered to short-action rifles. Only two years after its introduction it's already chambered by several major manufacturers, and both Winchester and Federal offer a very good selection of factory loads.
.270 Vs. 7mm
There are things you can do with a fast .30 caliber that you probably shouldn't be doing with either a 7mm or a .270. On larger game the .30's increased bullet weight and frontal area make a difference, and at very long range the wind-bucking ability and downrange energy of a fast .30 with aerodynamic bullets cannot be excelled.
On the other hand, I do not believe there is a significant difference between the .270 caliber's .277-inch bullet and the 7mm's .284-inch diameter. Realistically, the difference isn't worth arguing about, so I'm not going to try. I'm only going to restate that the .270 WSM has a commercial advantage in that it has only two .270 cartridges to compete against. And, deep down, I must be a .270 fan.
FAST, FLAT, SWEET
The .270 remains a great cartridge, but the .270 WSM is even better. Velocities for .270 factory loads vary considerably from brand to brand, but if you look at the average "standard" load, the .270 WSM is about 200 fps faster, bullet weight for bullet weight. This is significant. Obviously, it flattens trajectory, but in real terms I'm not sure this is the important factor. With an aerodynamic bullet like the 130-grain Ballistic Silvertip and a 200-yard zero, at 400 yards the difference between the .270 (muzzle velocity of 3,050 fps) and the .270 WSM (muzzle velocity of 3,275 fps) is just 23?4 inches. More important to me is the difference in energy: 2,685 ft-lbs for the .270 with this load, 3,096 ft-lbs for the .270 WSM. An energy dividend exceeding 400 ft-lbs is significant, provided you can obtain it without unacceptable recoil.
This is one of the great beauties of the short magnums. The burning efficiency of their short, fat cases that allows them to generate their velocity while burning less powder than longer-cased cartridges with similar performance also keeps felt recoil surprisingly mild. I'm still not certain exactly why this is, but light recoil has been a consistent attribute of every single short magnum I've used. I won't advertise that a .270 WSM kicks less than a .270 Winchester, but I find it pretty hard to tell the difference.
So, supposing you can have a little bit flatter trajectory and a significant increase in energy without getting kicked into next week, you can house this package in a short-action rifle that's a bit lighter and handier. What does this mean? Most of the time, I'm not sure it means all that much. The .270 is a great deer/sheep/goat/antelope cartridge. It shoots flat enough and carries enough energy for at least 400-yard shooting, which covers everything most people need to do. My first use of the .270 WSM was on a mule deer in Utah, shooting a 130-grain Ballistic Silvertip. I got the shot at maybe 200 yards. I blew it badly and had to shoot the buck again. Flatness of trajectory meant nothing, and all that extra energy, which I misdirected, didn't do any good either. In other words, I wouldn't have done any better with a .270 Winchester, nor would I have done any worse. Shot placement always counts, and the .270 still shoots flat enough and with enough energy for most situations with deer-size game. The great value of the .270 WSM is that, with its energy dividend, it's just plain better for larger game and the most open country, thus it is more versatile. This presupposes that appropriate bullets are used.
© 2009 Intermedia Outdoors. All rights reserved.
