BIG FAT SHELLS

chuck

Has any body shot over a 1000 rounds of these FAT SHORT MAGS??? I think they are barrel burners, like the 220 swift and the 22-250. gun writers say they are great. For what thats worth, I dont think they get away from their computers to do any hunting or shooting.

JustC

I would have to say that with todays barrels, especially stainless steel, they will go 1500rnds or better. The fastest that a friend of mine burned out a 30-378 wthby mag was 1200rnds. That being probably the barrel burningest cartridge there is, I would say that the standard short mags will go well over 1500 and your ultra mags will probably go close to 1500 as well. Just a guess from what i have seen with the 30-378. I will definitely go stainless when I buy one though.

A great rifle with a junk scope,....is junk.

hitman

What causes barrell burnout to occur faster in some cartridges? Does accuracy drop of quickly?

Thanks,
Hitman

Tailgunner1954

There is a theory that a barrel (actualy it's the throat that wears/erodes) lasts thru X amount of powder. let's call it 100lbs (just a number out of the air), a rifle that uses 25 grains per shot will last 4 times as long as the rifle that uses 100 grains per shot.
Another thing that accelerates throat erosion is not letting the barrel cool between shots, a shot every 30 seconds causes more wear than a shot every 3 minutes.

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Some guys like a mag full of lead, I still prefer one round to the head.

JustC

Tailgunner has the theory very correct and well described. and Now, here is a twist, when you shoot wildcat cartridges and those which are basicaly overcharged for their barrel length, you are dealing with an intensification of fire. For instance, if you take a 308, and compare it to a 30-378wthby mag, you are dealing with the same caliber, correct? That being said, the amount of powder in the aforementioned cartridges is what gives them different balistic characteristics. The 30-378 will obviously be faster and flatter (shooting the same weight projectile) than the 308 due to it's far greater powder capacity. One must now reasonably conclude that the fire which bursts forth from the neck of the cartridge, when the bullet unseats itself on it's way down the rifling, will come in direct contact with the steel in the barrel throat. The greater the intensity of the fire, the faster it actually eats away the metal, and therefore, allows the bullet to enter the rifling destabilized, hence the loss of accuracy.

Wildcat and super magnum calibers have, by design, a larger and more voluminous internal powder capacity, which in turn yields the greater force behind the bullet as powder is burned, propelling it faster and with greater energy. The fact that you burn X amount of powder in one cartridge pushing the same weighted and calibered bullet versus burning 3X amount of powder in another cartridge pushing that round, eliminates the variable of caliber/bullet in the equation. So, comparing the propellants, one deduces that the fire being forced into the same size hole (cartridge neck and shoulders) from the rifle with 3X powder in the cartridge, is going to have a fire which touches the rifling, of far more intensity, than the cartridge which is forcing X pwder through the same hole. Just think of the difference in torch tips, if you know anything about them. The increased angle of the wildcat necks also forces the gasses and ignition to create greater pressures and heat, as they flow over a sharp angle toward the neck, and this contributes to erosion. All bullets erode throats of barrels EVENTUALLY, but some are faster than others.

that is how the throat becomes eroded faster in the "hot" or wildcat calibers, than in standard calibers. That's a small intro into what burns out a barrel, there are many other contributing factors as well.

A great rifle with a junk scope,....is junk.

Edited by - JustC on 06/19/2002 22:47:35

BoltactionMan

The erosion is actually caused by the flame itself burning away the metal. That is why letting the barrels cool properly helps them to last a while longer.

KC