Doh! Make Sure Your Ammo Fits Your Chamber!
If you don’t match your ammo to your chamber, bad things can happen, that’s for sure. A while back, Forum member BigBlack had an experience at the gun range that reminds us of the importance of safety when shooting. He encountered evidence that someone had fired the wrong cartridge in a 7mm WSM rifle. The problem is more common than you may think. This Editor has personally seen novices try to shoot 9mm ammo in 40sw pistols. BigBlack’s story is along those lines, though the results were much more dramatic. It’s too bad a knowledgeable shooter was not nearby to “intervene” before this fellow chambered the wrong ammo.
7mm-08 is Not the Same as a 7mm WSM
BigBlack writes: “I know this has probably been replayed a thousand times but I feel we can never be reminded enough about safety. This weekend at the range I found a ruptured case on the ground. My immediate thoughts were that it was a hot load, but the neck area was begging for me to take a closer look, so I did. I took home the exploded case and rummaged through my old cases until I found a close match. From my investigative work it appears someone shot a 7mm-08 in a 7mm WSM. Take a look. In the above photo I’ve put together a 7mm WSM case (top), the ruptured case (middle), and a 7mm-08 case (bottom).”
The photo reveals what probably happened to the 7mm-08 case. The shoulder moved forward to match the 7mm WSM profile. The sidewalls of the case expanded outward in the much larger 7mm WSM chamber until they lacked the strength to contain the charge, and then the case sides ruptured catastrophically. A blow-out of this kind can be very dangerous, as the expanding gasses may not be completely contained within the action.
Can’t Happen to You? Think Again.
This kind of mistake — chambering the wrong cartridge — can happen to any shooter who is distracted, who places even a single wrong round in an ammo box, or who has two types of ammo on the bench. One of our Forum members was testing two different rifles recently and he picked up the wrong cartridge from the bench. As a result, he fired a .30-06 round in a .300 Win Mag chamber, and the case blew out. Here is his story:“I took two of my hunting rifles I have not used for over 25 years to the range yesterday to get new scopes on paper, a .30-06 and .300 Win Mag. I had four boxes of old Winchester factory ammo (two of each cartridge), which had near identical appearances. I accidentally chambered a .30-06 round in the Sako .300 Win Mag rifle. It sprayed powder on my face and cracked the stock at the pistol grip. If I had not been wearing safety glasses I might be blind right now.
You should always wear protective eyewear, EVERY time you shoot.“I feel lucky and am very thankful for being OK — other than my face looks funny right now. I am also grateful for learning a valuable lesson. I will never put two different cartridges on the bench at the same time again.”
It’s even worse when cops make those mistakes. Our club hosts half a dozen small PDs for their training and we all descend on the place when they are done to police brass (which they steadfastly refuse to police themselves, so..). Plenty of 9MM’s shot in 40s&w and even a couple of 9’s out of .45acp’s as well which I did not think one could make happen. Scary.
One part of the problem was that the casehead wasn’t being held by the bolt, that WSM case head is a lot bigger than a .308; look how far the case is deformed up from the base.
Ha – that’s an ‘improved’ case and then some! I once managed to get a 223 Rem to chamber and fire in a 6.8SPC rifle – no pressure of course with the seriously undersize bullet, but it still managed to produce a magnificently swollen-body case with some small splits. It made me a lot more careful afterwards about checking ammo box labels before loading.
I found an odd-looking 9 x 21 case on my usual range.
I didn’t know they made a “belted” version……….
Faint signs of chamber flutes; maybe one of our “lads” tried to run some through one of their MP-5s?
They have .40 cal Glocks, but, as far as I know they still use 9 x 19 MP-5s.
bE SAFE RELOAD ONE BATCH OF SHELLS AT A TIME AND KNOW WHAT YOU ARE LOADING AND ONLY PUT AMMO ON THE BENCH FOR THE GUN YOU ARE SHOOTING AND ONLY HAVE ONE GUN OUT AT A TIME. a GUN CAN RUIN YOUR WHOLE DAY. jUST SAYING