KABOOM: The .223 WSSM and 6mmBR Disaster

This post was written by Dr. Jim and Mary Clary.

Under most circumstances, shooters don’t have to worry about chambering the wrong cartridge into the wrong rifle. After all, the cartridges are well marked and we all know which rifle we are shooting on any given day. In many cases, incorrect cartridges cannot be chambered–larger cases will not fit in smaller chambers, for example. No problem! That being said, I can tell you that even an experienced, careful and normally safe shooter can make a mistake.

The following is an account of just such a mistake that could have resulted in death or dismemberment. Fortunately, the shooter was not hurt, but the rifle was completely destroyed.

Last year, a friend purchased a Savage Precision right bolt, left port, single shot bolt action in 6mmBR Norma. It was an incredible prairie dog gun and he spent the summer burning powder and busting dogs. In October, he purchased a stainless steel Browning A-Bolt Varmint in .223 WSSM. The weather in the upper Midwest turned sour by the time he got the brass tuned up and he only got to fire it a few times before he was “socked in” for the winter. Thus, he spent his evenings loading ammo for the spring thaw.

During a break in the weather, he grabbed both rifles and a couple of bags of .223 WSSM and 6mmBR cartridges and headed to the range to check out his new loads. In case you are not familiar, the 6mmBR is smaller in diameter and a mite shorter than the .223 WSSM. Because of this, it will chamber in a .223 WSSM, but the .24 caliber bullet is too big for the .22 caliber bore. That is what happened to my friend.

The rest is history; when he squeezed the trigger, all hell broke loose. The entire bottom of the rifle blew out, including the magazine assembly. The explosion actually cut the stock into two pieces. However, the bolt held and amazing as it may seem, the .243 bullet was “swaged” right out of the .223 barrel.

Now, realize that my friend has been shooting all manner of firearms, safely, for over half a century. He is meticulous, thorough and conscientious in his approach to reloading and shooting. However, he made one mistake. He put some loose 6BR cartridges in a baggie as he packed up from a prairie dog hunt last summer, without noticing that the baggie was marked .223 WSSM in black marker. Then, when the break in his winter weather came, he grabbed the bag, believing it to be the WSSM cartridges and didn’t check the head stamp.

Couldn’t happen to you? How many times have we emptied our pockets of cartridges and dropped them into a plastic container on the shooting bench? How many times have we set down to a marathon reloading session, loading several calibers in a row? How many times have we put the wrong bullets, cases or primers into the incorrect container? My point is that even the safest of us can make a mistake. So, look at the picture above and take a bit more time when you reload your ammunition at home or chamber a round in the field. It might save your life.