Almoset ka-boom?

[oktavist]

These are both the same bullet. Federal .40 S&W from the same box.

Now granted, I was shooting this out of a 10mm barrel in a glock 21. I knew it wouldn't work great, but I was surprised at this. It actually cycled the gun and ejected good, but maybe these flat head bullets aren't good. Periodically get stuck on the feed ramp and my 26 pound recoil spring just smashes them.

I don't usually shoot .40 cal at all, and I'm surprised these bullets don't look like the casings are crimped. I don't know if that's common or not....

I'm just glad I was paying attention during my shenanigans.

[Trriemferent]

Yea you got lucky. It could have turned out real bad for you
Just so you know .... most pistol rounds are not crimped

[200Apples]

That's not good. I'd contact the ammo maker's regional sales supervisor. I had to do that once with Fiocchi, and was treated to excellent customer service.

26 lbs recoil spring is substantial, but, even so, that cartridge may have had insufficient neck tension. If you were shooting this in a gun chambered correctly for this cartridge (and reasonable alternatives, of which .40/10mm is, just as .38/.357 is, or .44Spl/.44Mag is), then you may have a case to have the rest of your lot # replaced.

In my case it was .308 where the brass itself was too long from rim to shoulder. It was one box of 20 with a bullet weight different than what I was shooting at the time. Fiocchi replaced it with two boxes.

[Ross]

Soooo let me see if I understand correctly. You break a cardinal rule by intentionally shooting a round out of a gun which isn't the correct size and then - actually post about it??

[TKM]

Did they look like that before shooting?

Or did the second one get shortstroked into the feed ramp?

[-hanko]

Yea you got lucky. It could have turned out real bad for you
Just so you know .... most pistol rounds are not crimped

Read up a little on a concept called "taper crimp". Pistol brass needs to be crimped to remove the minute "bell" that allows the bullet base to enter the cartridge mouth. Lee makes what's called a "factory" crimp die if that's what you need.

[jeremiah12]

I regularly shoot .40 cal out of my Gen 4 G29 and have never had a problem. I have used the 10mm stock OEM barrel and I have also used the Federal .40 S&W you are using with the flat head bullets.

When shooting .40 cal I do use the stock 17# recoil spring. When shooting 10mm I use a 21# stainless steel recoil spring. The heavier spring will not reliably cycle the .40 cal ammo. I get a fair number of FTF and FTE.

My best guess is the .40 cal does not provide enough energy to move the slide fully to the rear so there is enough time to eject the empty cartridge and then strip the new cartridge from the mag and load it into the chamber. The new cartridge gets partway up before being slammed into the lower edge of the barrel and then it slides into the chamber from there. The extra spring weight just adds to the force slamming the front edge of the bullet into the lower edge of the barrel.

Use a lighter recoil spring and you should be GTG. A search of the net shows many use spring weights up to 22# with .40 cal with little problems. I find I had some problems with a 21# spring, especially if anything interferes with the slide movement such as a little debris build up or the slightest amount of limp wristing. With the arthritis in my wrist, it is easy to limp wrist from time to time. That is one reason I like my Glocks, they help me maintain my shooting form.

[Chapped Hide]

Soooo let me see if I understand correctly. You break a cardinal rule by intentionally shooting a round out of a gun which isn't the correct size and then - actually post about it??

There is no problem shooting .40 through a 10 mm barrel, it's done all of the time.

Read up a little on a concept called "taper crimp". Pistol brass needs to be crimped to remove the minute "bell" that allows the bullet base to enter the cartridge mouth. Lee makes what's called a "factory" crimp die if that's what you need.

Yep, done with the seating die on my Dillon.

[socal147]

Makes me want to buy a 20

[oktavist]

Did they look like that before shooting?

No.

Or did the second one get shortstroked into the feed ramp?

Totally shortstroked into the feed ramp by my crazy heavy recoil spring.

There is no problem shooting .40 through a 10 mm barrel, it's done all of the time.

That's what I thought. This was my first time trying it.

[MurdaJ]

Looks like my box of Winchester .40

http://www.calguns.net/calgunforum/showthread.php?t=1374517

[Glock Fan]

I had a friend a few months ago shooting my 40 G22, he was talking and not paying attention to what he was loading into the mag and loaded 10 rounds of 9mm. 1st round cycled and sounded fine, second round sounded like a squib so I stopped him and checked things out, looked at the ammo, sure enough! Loaded it all with 9mm. Luckily nothing bad happened.

[omega]

using .40 S&W in a 10mm barrel?

I regularly shoot .40 cal out of my Gen 4 G29 and have never had a problem. I have used the 10mm stock OEM barrel and I have also used the Federal .40 S&W you are using with the flat head bullets.

When shooting .40 cal I do use the stock 17# recoil spring. When shooting 10mm I use a 21# stainless steel recoil spring. The heavier spring will not reliably cycle the .40 cal ammo. I get a fair number of FTF and FTE.

My best guess is the .40 cal does not provide enough energy to move the slide fully to the rear so there is enough time to eject the empty cartridge and then strip the new cartridge from the mag and load it into the chamber. The new cartridge gets partway up before being slammed into the lower edge of the barrel and then it slides into the chamber from there. The extra spring weight just adds to the force slamming the front edge of the bullet into the lower edge of the barrel.

Use a lighter recoil spring and you should be GTG. A search of the net shows many use spring weights up to 22# with .40 cal with little problems. I find I had some problems with a 21# spring, especially if anything interferes with the slide movement such as a little debris build up or the slightest amount of limp wristing. With the arthritis in my wrist, it is easy to limp wrist from time to time. That is one reason I like my Glocks, they help me maintain my shooting form.

wouldnt regular use of the shorter .40 S&W cartridge cause more chamber erosion? since it sits back further in the 10mm chamber?

[MurdaJ]

I had a friend a few months ago shooting my 40 G22, he was talking and not paying attention to what he was loading into the mag and loaded 10 rounds of 9mm. 1st round cycled and sounded fine, second round sounded like a squib so I stopped him and checked things out, looked at the ammo, sure enough! Loaded it all with 9mm. Luckily nothing bad happened.

Let my buddy shoot my g27, after the first few sounded weird and didn't cycle, I inspected the mag. Full of 9mm..