Ammunition Mixups

The gun store guys talk on the subject:

I’m always careful at the range when shooting similarly sized cartridges.  I’ve heard too many stories of people using the wrong cartridge, some by accident and some by mistake, with undesirable results.

Barry’s story about the .44 Magnum / .45 Colt WalMart mixup was pretty funny.

From a design standpoint the fact you can hurt yourself by using the wrong round is pretty poor.  I don’t want to go on a big “Darwin” rant, because if you’re not paying perfect attention, and you don’t know all that much about firearms it would be incredible easy to have happen.

Anyone ever have a bad day because of an ammo mixup?



Bear January 15, 2012 at 01:16 am

No, but I have an uncle who in his youth put 5.56 ammo in an inexpensive .223. The result was a blown chamber and severe arm lacerations. The bullet was found in a wall or something near him.

Frank January 15, 2012 at 03:08 am

Never had a bad day, I do my best to examine my ammo.

PP January 15, 2012 at 04:34 am

No, almost did, though.

When I was new to guns, I rented a WASR-10 at my local gun range. But the guy handed me a box of 5.45×39, so I thought it was a 74 or something. Gun still fired, but didn’t cycle. Keyholed every shot.

That’s when I finally realize that the guy at the counter fucked up (as did I), hurr.

Crunkleross January 15, 2012 at 09:58 am

Ok so what’s the point? At first I thought don’t shoot the wrong ammo then they say S&W said it was ok and then to top it off they purposely shoot the wrong ammo in a cheap gun and nothing bad happens. I think they like to hear themselves talk. Oh and yeh don’t buy the big cheap crate of ammo at the gun show!!!!!!

Rich January 15, 2012 at 10:38 am

3 things …

First, just because a cheap gun will hold up to a mistaken round, doesn’t mean that a more expensive one is stronger.

Second, I shoot .357 Maximum in a TC contender. If I recall correctly, It’s a dead ringer for an older black powder round. I don’t remember which one. I was told that it would be deadly.

Third, they talk about wrong and “don’t do it”, but they don’t stress “could turn your gun into a grenade”. I wish they had. Not everybody viewing it will be a gun aficionado.

Dano January 15, 2012 at 12:42 pm

I’ve never had an ammo mix up, but Grandpa told me about one on a bird hunting trip many years ago. One of the fellas was loading his shotgun and dropped a 20 ga shell into his 12 ga. Some time later, when checking his gun, seeing it was not loaded (the 20 ga shell dropped far enough into the chamber) he dropped in a 12 ga shell. Fortunately, he did not fire the gun and discovered what had happened later on when swabbing his bore at the end of the day. From then on, they made a rule on their trips that everyone would bring the same gauge shotguns.

Vhyrus January 15, 2012 at 12:51 pm

My family was at my Grandpa’s house once and we found an old 22 pump action and decided to take it plinking. After having a really rough time with it (lots of jams, difficulty working the action, etc.) we decide to call it a day. Once Grandpa got home we asked him what the problem with that gun is. Turns out we forced a box of 22lr through some rare valuable antique that shoots some unheard of obsolete 22 cartridge like .22 WRF and that we almost destroyed an irreplaceable gun. Oops….

Pilotgeek September 12, 2012 at 12:43 am

.22 WRF is really similar to WMR, which is still used today. I doubt .22lr would “almost destroy” a WRF. You may wind up with a few split cases, and like you said, feeding issues, but a .22lr is a really low pressure cartridge.

gunbarrelflygirl January 15, 2012 at 07:32 pm

You know, this is interesting because, I think there’s a pretty big knowledge gap out there for women. I wouldn’t shoot anything other than what was intended for the gun I was using – I wouldn’t even have thought of putting a different round in. BUT, I STILL don’t have enough understanding of cartridges!! And that’s after multiple instructional “lectures” from my husband… So, Barry, I would like to see you do something geared specifically toward women. What I get confused about is all the back and forth between metric (e.g. 5.45×39) and inches (.223) and calibers. Is there an online resource for women in this dilemma, or, do I just need to sleep with “Cartridges of the World” under my pillow?

Vhyrus January 16, 2012 at 01:07 am

I can help you with the metric vs. imperial. It’s actually really simple: Metric sizes are usually military rounds with inches/calibers are civilian. Certain cartridges are either created from or alongside other cartridges so they are interchangeable with others. For example, 5.56 X 45 and .223 are roughly the same size, but 5.56 is chambered for a higher pressure. Any gun that shoots 5.56 can shoot .223, but most guns labelled as .223 cannot shoot 5.56. That’s probably the trickiest one. Anything with ‘x39’ is soviet (e.g: 5.45×39, 7.62×39) and as such usually is made for an AK. 7.62×51 is interchangeable with .308 winchester so they are considered the same round. Theres also 3 different types of 9mm (I think they went over that in the vid so I won’t redress it.) That’s about the worst of it.

RH January 16, 2012 at 12:38 pm

9mm/38 is a whole can of worms by itself.
9mm was the standard European nomenclature, 38 was American, and you occasionally have firearms that use a less common name for a common cartridge, such as .380, 9mm kurz, or 9×17 Browning.

Not to mention dealing with all the variations on cartridges for that bullet diameter, like 9mm largo, 9×18, 38 ACP and Super, the various 38 revolver rounds, or if you get into collecting older military firearms, there’s another few European cartridges, and few of the guns have cartridge markings.

On the subject of ammo mixups, my father bought a 1903 dated Colt New Navy in .38 Long Colt from a pawn shop in the early 60’s, and shot 38 special through it until a couple of years ago. Besides being higher pressure, 38 special has a smaller diameter bullet than 38LC and would keyhole. He always thought he was just a bad shot.

paul kimble January 16, 2012 at 11:09 pm

Actually be careful shooting commercial .308 in firearms chambered for 7.62 NATO. 7.62 NATO’s chamber pressure is 49,700 CUP while commercial .308 is 52,000 CUP. There is also a 7.62 CETME round with a chamber pressure of 46,800 CUP.

Although the above pressures SHOULD be within the margin of safety I watched a friends Chilean M1895 re-chambered for 7.62 NATO rapidly disassemble itself while firing .308 Winchester.

Cameron January 16, 2012 at 04:41 pm

Look on your gun for the cartridge. Then go to or, type in the cartridge.

At Google, you can get other names, and even find places that sell the ammo.
At Wikipedia, you simply get other names for the cartridge.

Problem solved.

Nick January 16, 2012 at 04:10 pm

Almost ruined a friends XD45 when I was taken shooting for the first time about 4 years ago. I had never really handled a gun before and he handed me a big handful of .40S&W and 45AUTO. Which to the lamen, are the exact same size. I ended up firing a 40 out of his gun, split the brass, and he had a hell of a time clearing it from the weapon.

AMB January 20, 2012 at 03:49 pm

I had a similar experience at the range a couple years ago. A friend of mine was looking to buy a gun and so he went and rented a couple at our local range. I walked him through the manual of arms for the 9mm and the 40 he’d rented. Watched him shoot the 9mm a few times, then left him to his own devices while I set up on the lane next to him.

He switched to the 40 and, not realizing that the boxes of ammo we’d bought were different, he loaded a mag half full of 9mm. He asked me why the 40 “had to be cocked every time” and I looked at the ejected brass. The 9mm wasn’t cycling the action (of course), and the cases were fire-forming to the barrel.

James January 16, 2012 at 07:04 pm

I was picking up some plinking .223 ammo at Wal-Mart one time. I specifically pointed at the ammo that I wanted and asked for four boxes.

Got home, looked at my boxes, and lo and behold one of them was .222 Remington – which I believe is so similar dimensionally to .223 that it will chamber.

Needless to say I was pissed – I returned it, even though they “don’t allow returns on ammo.” They said they couldn’t sell it to another customer, I said fine – turn it into the Sheriff’s office to be destroyed. I eventually escorted a manager to the ammo case where the .223 and .222 were literally stacked on top of each other interchangeably and she agreed that they “probably made a mistake” – well DUH! Needless to say, I check every single box now when I buy multiple boxes of ammo from *anywhere*.

Jim C. January 22, 2012 at 06:19 am

Is turning it in to the sherrif’s office the best way to dispose of old ammo? I had a bunch of reloads from my grandfather, and they were a bit too much for his revolver. I ended up running them through anyhow… Didn’t really harm the gun, the extractor came off but went on really easily afterwards…

gunbarrelflygirl January 17, 2012 at 09:06 pm

Ahh, thanks guys for all the educational help! But, Vhrus, you sound like my husband, rattling off all the numbers. LOL! Like I said, I guess I’ll have to sleep with “Cartridges of the World”under my pillow at night!

J.Yarbrough March 8, 2012 at 10:06 pm

Thankfully, I have never experienced a munition mix-up. When I load my magazines, not only do I check the manufacturer’s stamp on the butt-end but I also thoroughly wipe away any and all grime and debris associated with the manufacturing, shipping, and merchandising of my ammo. I have seen some really dirty cartridges from some of the more well-known makers so just a tip to ensure your weapons’ longevity!

Eric March 9, 2013 at 09:00 am

purchased a new smith and Wesson govner .410/45 and went shooting with some friends and the old man on my birthday, we were shooting some older ammo mostly .45 but somehow a .44 mag round got caught in the mix not sure how but the gun hasn’t been functioning since. i’m going to send it back to the company to see what they think but i just wanted to get a little input before i did. the hammer is difficult to pull back and the chamber is very hard to close and almost impossible to open i can chamber to different cylinders but it is difficult. mainly my question being is there any hope in saving the gun? only got to shoot it once :(

Crunkleross March 9, 2013 at 02:29 pm

Send it back to the factory, so many things could be wrong or not, if they fix it you can be sure it is safe. If it’s junk or if it just costs money to fix count it as lesson learned.

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