Understanding The New Magnums

Unbelted, full-length, short, super short, ultra, short-action ultra. Do you have a handle on all the new magnums that have come along in the last few years? Does anyone? Some serious rifle cranks--and a few overworked ballistics technicians--have undoubtedly acquired some familiarity with most of them, at least as far as accuracy and load development goes. But probably nobody has more than a passing field experience with all of them, because there are just too many of the darned things.

Oh, we might get a chance to take a new cartridge out and kill a deer or an antelope with it, maybe a couple caribou. We call that "field tested," but no two field situations are exactly alike, so one or two good results (or bad) are hardly definitive for the performance of a cartridge or bullet. I don't know at what point we pass from slight familiarity to genuine knowledge, but I'm sure it's somewhere in the double digits of game animals taken. I can lay that claim with a couple of the new cartridges.

The funny thing about our huge numbers of new magnums is that in-depth field experience isn't as important as it may seem. This is because almost none of these cartridges break genuinely new ground in terms of field performance.

Similar Stats

Remington's full-length Ultra Mags develop similar velocity, caliber for caliber, as do Weatherby's full-length magnums. The anomaly is the 7mm Ultra Mag because it has no Weatherby counterpart (Weatherby's 7mm has a case shortened to .30-06 length); its existing counterpart is the 7mm STW. Depending on who is doing the loading (and the chronographing), the Ultra Mags may be a little bit faster thanks to their fatter cases. But the difference isn't significant, and since we already know what 7mm, .308, .338 and .375 bullets do at these velocities, there shouldn't be much mystery.

Similarly, the Short magnums from Winchester and Remington's Short Action Ultra Mags offer about the same performance as existing belted short magnums, whether we're talking .270, 7mm or .30 caliber.

It's difficult to make comparisons as direct with Winchester's Super Short magnums, but the .223 WSSM isn't really faster than the .220 Swift. The .243 WSSM is definitely faster than the .243 Win., although not as fast as the .240 Wby. Mag. So my premise is the same: We've known for years what .223 and 6mm bullets at these velocities will (and won't) do.

Lazzeroni's cartridges are indeed a bit different. Whether short or long, they are all the fastest in their class, but is the performance category really unique? The short Lazzeroni cartridges produce velocities somewhere between the .30-06-length belted magnums from Winchester and Remington and the full-length belted magnums (Weatherby, STW). No mysteries here.

The long Lazzeroni magnums are faster than anything else, including the .30-.378 and .338-.378 Wby. Mags. But are they so much faster as to put them in a different performance category? I don't think so.

So in terms of velocity and energy, the new magnums don't offer anything that's truly new, but that doesn't mean they have nothing to offer. They do have their strengths, and before you buy one of them, make sure you know what those strengths are.