Right Rifle, Sherlock. Wrong Cartridge

Apr 24

What happens when you fire the wrong cartridge in the right rifle? Usually nothing good. If you found the empty case shown in this photo, would you know what happened to create it? Sherlock Holmes would know immediately. Someone chambered a .300 Winchester Magnum in a .300 Weatherby Magnum chamber and fired it. The shorter .300 Winchester brass tried to flow out and forward to fit the larger space, but ran out of material and elasticity, thus the short neck and that dangerous split in the shoulder. I came across split cases like this at two shooting ranges last year alone. Apparently the shooters did not know that there are differences in .300 magnums. Fortunately, few .300s will fit and ignite in mis-matched chambers, but the above combination will because both are built on the .375 H&H belted magnum case which headspaces on the belt rim. This means the shorter Winchester cartridge will be held tightly in position while the firing pin slams forward, resulting in ignition. Excessive chamber space (headspace) is never good. Pressures can rise when the bullet, already moving at substantial velocity, suddenly slams into the rifling, which acts like a brake. This creates a dramatic and potentially dangerous spike in pressure. Depending on the burning rate of the powder, the barrel could split or the locking lugs in the action fail. Flying metal can cause serious damage, even death. Even more danger results when the wrong bullet diameter (caliber) is fired. I once, in a fit of distraction and stupidity, stuck a 7mm-08 Remington in a Dakota #10 rifle chambered for a .25-06 Remington. It went bang, no hole appeared in the paper target, and the chronograph displayed 400 fps more velocity than it had for two previous rounds. When I opened the action, the primer fell out. The head was black with soot, and when my befuddled brain finally read and comprehended the 7mm-08 Rem. stamped in the brass head, I about jumped off the bench. Fortunately the .284-inch Hornady SST bullet I'd fired was soft enough to squeeze down the .257-inch bore without splitting the barrel. And the massive Dakota falling breech block was strong enough to contain the pressures. There is no belt on the 7mm-08 Rem., but it and the .25-06 are made from the same .30-06 parent case. The body taper alone is sufficient to hold them securely enough for a firing pin to work. The scary thing about this is that the .308 Winchester, .338 Federal and .358 Winchester are also built on that same case. I doubt any barrel would stay in one piece while those substantially larger diameter bullets tried wriggling down a .257-inch hole. The .270 Win., .280 Rem. and .30-06 are all built from the .30-06 case, but the shoulder of the .280 is pushed slightly forward, making it too long to fit in either of the other two chambers. A .270 Win., however, could fit and fire in a .280 Rem. or .30-06 chamber. A .308 Win. will ignite in a .30-06 chamber, too, as will the .338 Federal and .358 Win. Dangerous! There are various other mismatched combinations, some of which can be extremely hazardous, so beware. Never, ever insert the wrong ammunition into the right chamber. Always read the designation on the head of each cartridge plus the caliber/cartridge designation stamped into the rifle barrel. Don't read only the cartridge information on the box. The wrong cartridges are sometimes stuck into the right boxes, too, especially in a hunting camp where various people shoot similar cartridges or ammo. Uncle Bob grabs nephew Tim's .270 Box and puts a few of his .30-06 rounds in it. Grandpa find a few lose .308 cartridges and neatly inserts them into Bob's .30-06 box. Yikes. Statistically, rifle shooting is remarkably safe. You're more likely to be seriously injured while boating. But shooting is still potentially deadly. Practice caution and safety at all times. Don't joke around. Don't play practical jokes on the range. And double check that ammo. The .300 Winchester Magnum and .300 Weatherby Magnum are close, but not close enough. # # #

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