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View Full Version : standard v. magnum calibers


GBullet
02-10-2005, 10:11 PM
The appelation of "magnum" can be subjectively attached to a cartridge. Magnum is a term that came into use 400 years ago to describe a larger than normal champagne bottle, like the one that GBullet opened on Mardi Gras. ;) It comes from the Latin magnus, meaning large. Despite the inaccuracy of the term, when we speak of a magnum hunting rifle cartridge, other shooters equate the magnum cartridge as being beefed up.

Consider two rifle cartridges, one standard ("S") and the other magnum ("M"). Suppose that S is loaded with 30 grains of powder and fires a 125 grain bullet at 2700 fps. Suppose that M is loaded with 45 grains of powder and fires a 150 grain bullet at 2700 fps.

At first glance, M seems like a good deal and it is a nice package. It shoots a heavier bullet at the same velocity. M gives us more 20% more power and a bit more range than S. Could we have overlooked something?

The clue here is that the specifications of S and M were not chosen arbitrarily. In our example, S is the .276 Pedersen and M is the pre-WWII loading of the .30-06 Springfield. Though the .30-06 has never been called a magnum, it offers magnum performance compared to the .276 Pedersen. These two cartridges were chosen because they were extensively tested against each other by the U.S. Army.

The recoil of the .276 Pedersen was about the same as the recoil of a .243 Win. Now, I'm sure that we're all a bunch of tough he-men, and a few ladies, who practice every weekend with our .30-06 pocket pistols. Regardless, the soldiers who performed the tests did far better with the S (.276 Pedersen) than with the M (.30-06). Significantly, soldiers firing the .30-06 became tired much more quickly than did the soldiers firing the .276 Pedersen.

Recoil is a complicated phenomenon. Obviously, increasing the bullet weight while maintaining the velocity increases the recoil. What is often overlooked is the effect of the added powder. Adding more powder, even without any change in performance, increases recoil. It adds to the ejecta (stuff that goes out of the barrel). If that isn't enough, pressure and efficiency problems crop up as you increase the ratio of powder to bullet weight.

Magnums normally have to use longer barrels to offer any great advantage over standard cartridges. Since magnums are typically longer and wider than the standard cartridges they surpass, magnum rifles are longer and heavier. So for the sake of a modest increase in power, you get to carry a rifle that is 2 pounds heavier, snags on every bush, and kicks you until you drool.

Some magnums are still mild kicking and can fit in a normal weight rifle, like the .243 WSSM. Still, the .243 WSSM needs a 22" barrel to be worth the drawbacks.

I apologize if I seem anti-magnum. However, I have learned that a modestly powered cartridge and good shot placement will beat a flinch-shot magnum every time.

Magnum88C
02-10-2005, 10:35 PM
I pretty much agree as far as rifles go. I have one magnum, a .375 H&H. i bought it because I was looking through a magazine (American Rifleman, I believe) and saw the No1 in stanless/black laminate. I got to thinking if I had one of those what would my caliber of choice be? I came up with .375 H&H for several reason, so I bought one. So it was out of a liking of the uniqueness of the weapon, rather than a feeling of "need" that I got it. Other than that, all of my rifle calibers are of "standard" chamberings.

In handguns, I DO prefer magnum chamberings,a s I think handguns are underpowered to begin with, which is a trade-off for their portability and concealability.

BTW, magnums are ususally considered for catridges of the same caliber. I.e. the .300 Winchester Magnum is a magnum in comparison to the .30-06 and .308. So I would disagree that the .30-06 would be considered a magnum of the .276 Pedeerson, as they are different calibers. Although the comparison made your point.

Chippathingy
02-10-2005, 11:25 PM
Pretty basic stuff.

GBullet
02-11-2005, 12:19 AM
Let's look at this another way...

According to the Speer Reloading Manual, a .30-06 loaded with 59 grains of IMR 4350 will fire a 150 grain bullet at 2834 fps. That same book states that a .300 Win Mag loaded with 69 grains of the same powder will fire a 200 grain bullet at about the same speed (2843 fps to be exact). I've chosen these two because they use the same powder (same combustion properties). While the .300 WM will give us 34% more muzzle energy, the recoil of the .300 WM should be about 61% higher. Thirty-four percent more energy for 61 percent more pain? Nah, I don't think so.

Then there is another little nasty...the LaGrange correction.

As you increase the quantity of powder for a given weight of bullet, the difference between the chamber pressure and the pressure on the bullet's base increases. Remember, the combustion energy has to push both the bullet and more propellant mass.

Disclaimer: If you just want a rifle chambered for .475 Bear Stopper Magnum, buy it. If for no other reason, this is America and you are free.

brass hammer
02-11-2005, 12:25 AM
Pretty basic stuff.
well ,,,CHIP,[I BROKE A GUYS NOSE ,ONE TIME ON THE JOB-SITE, I CAUGHT SMOKIN' POT, NAMED 'CHIP']
it is pretty basic 'stuff'

but i like it !!!

andy
02-11-2005, 01:31 AM
no you aint free. try not paying taxes, or your car insurance or license plates, and SEE how "free" you ain't. Some people really CAN utilize the extra range and power of the magnums, but they are rare men indeed. A few thousand in the Entire USA.

GBullet
02-11-2005, 01:39 AM
no you aint free. try not paying taxes, or your car insurance or license plates, and SEE how "free" you ain't.

Touche', andy, you're right about that.