It's Possible to Shoot 9MM in a .357 Sig

[Bottom Gun]

When I’m reloading, I keep a can near the press for what I call “factory seconds”. These “seconds’ are rounds that are less than perfect for various reasons. Usually it’s because I didn’t like the way it felt when I seated the primer or the bullet. For whatever reason, I gage the round then put it aside as a “second” for practice only. I’ve never had a “second” round fail but I don’t want to depend upon a less than perfect round so I separate them.

I was shooting a few .357 Sig “seconds” the other day at a paper target. I had a pretty good group going when I dropped the hammer of my P229 on a short round. It felt and sounded much different than the other rounds I had shot. This round was notably less powerful than the previous rounds and, in comparison to the full power .357 Sig rounds I had been shooting, it felt almost like a squib round.

The bullet did come out of the barrel though and it struck the target approx 5” above the group I was shooting, a sign of a lower power round. The slide cycled and chambered the next round in the magazine.

This really concerned me. How in the world could I have gotten a reduced powder charge in that short round? I’ve never had a powder issue in my 40+ years of reloading. It really shook my faith in my ability and the thought nagged me the rest of the afternoon.

Later, when I was sorting through the brass from my session, I saw a very strange looking case. That’s when it all made sense. See attached pics.

Apparently some senile old fool threw a round of 9MM into the wrong “seconds” can and it ended up mixed in with the .357 Sig “seconds”. That same old fool must have somehow failed to notice the 9MM round when he absentmindedly loaded a magazine with .357 Sig and ended up shooting the 9MM round out of the .357 Sig pistol.

Despite the off center primer strike, the round fired and the 9MM brass conformed to the .357 Sig chamber.

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[R.W.Dale]

In a lot of modern pistols the extractor plays just about as big a role in headspace as the chamber. As you have discovered.

 

[<*(((><]

It's good to see that blazer brass is up to the task!

 

[Zaydok Allen]

Hey it bulged to just the right shape! Loader her up again!

 

[CZ9shooter]

Looks like a 9mm I fired in a 40sw one time. Had two Ruger SRs at the range. A 9 and a 40. Grabbed the wrong mag by mistake. I imagine this happens more frequently with Glock owners. They all look the same!

 

[pblanc]

Yes, I accidentally shot a round of 9x19mm out of my .40 S&W SIG P229 once. No big deal. The case was bulged a bit. Not something to make a habit of.

 

[greyling22]

I've seen a 40 fired in a 45 that liked like that. And a 9 in a 40. It is more common than you might think. (These were things I have seen, not done. Closest I have done is loading and firing a 380 and a 9mm mak through a 9mm lugar gun.

 

[kemikos]

I've seen a 40 fired in a 45 that liked like that. And a 9 in a 40. It is more common than you might think. (These were things I have seen, not done. Closest I have done is loading and firing a 380 and a 9mm mak through a 9mm lugar gun.

That last is actually pretty dangerous. 9x18 has a lower charge than 9x19, obviously, but it's also a larger diameter bullet (it's actually 9.2mm). That means a much tighter fit, which can mean vastly higher pressure, similar to a barrel blockage.

I'm glad it turned out ok for you, but I've heard of kabooms caused by doing just that. Do not recommend.

 

[grampajack]

In a lot of modern pistols the extractor plays just about as big a role in headspace as the chamber. As you have discovered.

Can you explain that to me? I have absolutely no idea what you mean so maybe this is a learning opportunity for me.

 

[R.W.Dale]

Can you explain that to me? I have absolutely no idea what you mean so maybe this is a learning opportunity for me.

The textbook explanation is that headspace for a pistol cartridge only happens from a shoulder or case mouth against a corresponding cut in the end of the chamber.

Reality is extractors are so good now a lot of modern autoloaders will bang away the next size ammo down (unintentionally of course) with seldom a hiccup

 

[CZ9shooter]

The extractor will hold onto the case rim well enough to keep the cartridge firmly seated back against the breach face allowing the firing pin to strike it with enough authority to ignite the primer. Without a good extractor the case would just rattle around in the chamber with little chance of a good pin strike.

 

[grampajack]

Ah, I see what you mean. I thought you meant the extractor somehow influenced the actual headspace. All clear now.

 

[greyling22]

That last is actually pretty dangerous. 9x18 has a lower charge than 9x19, obviously, but it's also a larger diameter bullet (it's actually 9.2mm). That means a much tighter fit, which can mean vastly higher pressure, similar to a barrel blockage.

I'm glad it turned out ok for you, but I've heard of kabooms caused by doing just that. Do not recommend.

I suppose I was unclear there. I have reloaded a 380 and a 9x18 case as 9x19's. The tricky little cases snuck into my brass bucket and were loaded in the progressive. Didn't notice them until I loaded them in the mag and saw extra bullet sticking out of the case. They fired fine, but then, I load light.

 

[vaalpens]

The primer strike does not look like a Glock primer strike. If it was a Glock then maybe you would have had a case with a Glock and SIG bulge at the same time.

 

[wally]

You aren't the first and likely won't be the last to do such a thing. Years ago I was at the range and the guys next to me were complaining about their new Glock 22 and that "damn cheap Blazer ammo" getting all manner of malfunctions and "split" cases along with terrible groups. Seems they were shooting 9mm instead of .40S&W, problems went away when they shot the correct ammo

I suppose I was unclear there. I have reloaded a 380 and a 9x18 case as 9x19's. The tricky little cases snuck into my brass bucket and were loaded in the progressive. Didn't notice them until I loaded them in the mag and saw extra bullet sticking out of the case. They fired fine, but then, I load light.

Been there done that, but the 9x18 cases generally don't enter my shell holder, so I can't say I've ever loaded and shot one as a 9mmone. The 9x18 factory ammo generally won't chamber in a 9mm pistol.

 

[Tallball]

My shooting buddy is something of a perfectionist and prides himself on how careful and mistake-free he can be.

However, I was standing next to him when he somehow loaded a 380 along with a bunch of 9mm rounds into... I think it was his Beretta. When he got to the 380 it fired, but the brass got hung up inside or something and he had to put it away and field strip it when he got home. The funniest part was him grumpily answering, "Nothing" when his wife innocently asked him what he was doing when he was manipulating it to get the spent case out.

I tried to do it the other way. I was absent-mindedly wondering why I couldn't get a round into one of my 1911 magazines. After looking closer, I realized that I was unlikely to ever fit a 45acp round into a 40 caliber magazine.

 

[mjsdwash]

\

I tried to do it the other way. I was absent-mindedly wondering why I couldn't get a round into one of my 1911 magazines. After looking closer, I realized that I was unlikely to ever fit a 45acp round into a 40 caliber magazine. [/QUOTE]



I watched a new (2) gun owner struggle with this for several minutes before asking for help.... I also saw the look of confusion as a 40 went off in the 45 a few minutes later.

 

[Pablito1]

Back in the early 1980s several of us were practicing pistol silhouette shooting with mostly Contender single shots. A lady picked up the wrong pistol thinking what it was a 30/30 but it was actually chambered for a 41 Mag. The bullet hit the ground about 20 yards in front of us. The brass case just expanded out to fit the internal dimensions of the barrel.
Regards