What do you call this?

[blgarin]

This was fun (not).

Yesterday I got a bit of a scare. Still have all fingers but recoil spring wasn't so lucky.

This was a 9mm, 124g lead cast, 4.0 Red Dot load from a HighPoint (which is rated for +p. I've fired it a bit before and, obviously, not had this problem.

Was this a bad case? Too hot a load? Something mechanical (the "hole" is very rectangular)?

Hopefully the pictures upload or this post isn't going to make a lot of sense.
gb

 

[guyfromohio]

I'm not the most mechanically inclined person, but it looks like there was a gap in the chamber allowing the case to bulge and burst.

 

[243winxb]

A bulge at the extractor cut may have kept the round from fully chambering, firing out of battery. Or just a plain double charge of Red Dot . Or Defective brass. I am going with double charge of powder. Glad you still have all your fingers.

 

[rcmodel]

Thats a blown case.

Pressure blew it out where it was not supported at the feed ramp cut.

Depending on the bullet design you are using, 4.0 Bullseye might be over Max.

Look at all your fired cases and see if you are consistently getting 'guppy belly' case bulge there.

If you are, back off the charge, you are on thin ice.

Or it could have been caused by a Max load of Bullseye + bullet set-back during feeding.
Check your case neck tension.

If not one of those, you way over-charged that one somehow.

Rc

 

[jaguarxk120]

What gun did you fire this round in, that would help in finding out what happened.

 

[Rico567]

You blew out the case head. I'd guess overpressure was the cause, but I'm not in possession of sufficient facts to make an informed judgment.
Case looks just like what the steel Commander in .38 Super I used to own would do to a case when I'd try to go hot. This was over 30 years ago, and it's a different world out there, lots of improved powders for the Super. I was loading Win. 540, an it was completely predictable: 1/10 of a grain under = nice indented bulge; 1/10 grain more than that = blowout. Luckily, I had bought the gun and dies dirt cheap, and managed to sell them right.

 

[nevadabob]

But he used Red Dot.

 

[blgarin]

The gun was hi-point c9. The case isn't w/ me right now but I believe is has a PPU stamp.
I'll check for the bulge on other cases.

 

[sexybeast]

Case failure and it may have been out of battery by the looks of the rim going around the case.
4.0 of Red Dot is not max for a 125gr bullet but it is more than I would use for lead. Pressure should not have been too high even with some bullet setback.
Hi-Points are not known to be quality firearms. Do this experiment: With the gun unloaded pull the slide back ever so slightly and see if it will operate [striker release when the trigger pulled] and that may have been what happened.
This same thing happened to me once with a Taurus pt92, case blew out right above the slight gap where the feedramp is [unsupported area]. Quite a suprise and all that happened was the trigger spring became disconnected.

 

[GaryL]

That looks like an out-of-battery failure. Case appears to be bulged all the way around.

ok, I agree with sexybeast.

 

[blarby]

is it just me, or does this pressure deformation go all the way around ?

beat me to the submit gary, lol

 

[fiftybmg]

This is a common problem with reloaded ammo out of an unsupported chamber.

 

[jaguarxk120]

The High Point C9 is a blow back operated pistol, NOT a locked breach gun.

The reloads you were using were for locked breach guns. When the gun fired the slide started to move back before case pressure was low enough and there was a case rupture.

The pressure ring around the case shows that the case was being extracted while under high pressure. The 9MM Luger case is tapered and could not expand enough to grip the wall of the chamber under high pressure.

You may have used this loading in the past but the law of averages has caught up, a thinner/weak case and heavy loadings.

 

[Wil Terry]

A case like this one can only blow out like that where it is unsupported over the feed ramp. Using topend loads in blowback pistols all but invited it to happen.

 

[blgarin]

Thanks for all the info friends. It sounds like 4 g of Red Dot, in this gun, is too much. I was also firing the gun rather quickly which may fit with what jaguarxk120 was saying about ejecting under pressure.

I'll give the experiment that Sexybeast suggested a try.

gb

 

[Walkalong]

I am going with double charge of powder.

I'm going to agree.

 

[rcmodel]

I was also firing the gun rather quickly which may fit

There is no possible way any human can fire a gun so rapidly it causes blown cases.

rc

 

[buck460XVR]

I too was gonna guess an out-of-battery failure. But jaguarxk120's reply makes a lot of sense.

The High Point C9 is a blow back operated pistol, NOT a locked breach gun.

The reloads you were using were for locked breach guns. When the gun fired the slide started to move back before case pressure was low enough and there was a case rupture.

The pressure ring around the case shows that the case was being extracted while under high pressure. The 9MM Luger case is tapered and could not expand enough to grip the wall of the chamber under high pressure.

You may have used this loading in the past but the law of averages has caught up, a thinner/weak case and heavy loadings.

 

[tyeo098]

2 options:

1) Double charge caused the case to be extracted under high pressure, when it was extracted pass the thick webbing the thin wall blew out.

2) Fired out of battery, case never seated all the way in the chamber, side wall blew out.

The reloads you were using were for locked breach guns. When the gun fired the slide started to move back before case pressure was low enough and there was a case rupture.

Nah, the 10lb slide of the C9 is enough to withstand the beatings of normal and +p loadings. This was something extraordinary that would have happened in a 100$ C9 or a 700$ Glock, they are both recoil operated.

 

[LiveLife]

I would rule out double charge as 8.0 gr of Red Dot and Promo will spill over the case.

OP did not post how the powder was measured/metered but 2004 Alliant load data lists 4.5 gr as max charge for 125 gr lead bullet at 1.150" OAL and even up to .2-.3 variance I have seen with Pro Auto Disk would have dropped 4.2-4.3 gr charges. It is for this reason why I used 4.0 gr Red Dot/Promo with various 124/125 gr lead RN bullets with OALs from 1.080"/1.100" (non-stepped RN) to 1.125" (stepped RN).

I am with rcmodel that shooting rapidly would not cause blown cases - if that was the case, how do Uzis and MP5s function in full-auto without blowing up cases?

 

[matworz]

My first thoughts went to out-of-battery.

 

[SAGEEN]

I belive it is an over charged load check your loads ...go back to the books not just one look at a few different listings and compaire to your load ..don't shoot any more till you figure out the cause bad things can happed quickly

 

[jaguarxk120]

tyeo098 the c9 is blow back operated and the Glock is a locked breach gun.

The c9 ,as you say 10 pound slide on the c9 is enough to withstand the beatings of normal and +p loadings.
This may be so on most blow back guns but we have no way of knowing the condition of this c9.

One major factor in any recoil operated gun is the "recoil spring" and in a blow back gun it is a major factor, if the spring is weak the slide will open sooner during the firing cycle.

Recoil springs do have a service life and have to be replaced sooner or later.
The 1911 shooters know this and the target shooters keep several spring on hand depending on what level of power they are shooting. If you look in Brownells catalog there are several different weights that can be had.

The c9 is more of a service pistol and during it's service life the recoils should be replaced.

 

[tyeo098]

One major factor in any recoil operated gun is the "recoil spring" and in a blow back gun it is a major factor, if the spring is weak the slide will open sooner during the firing cycle.

Right, but the inertial mass of the slide is what keeps it locked during firing, not the spring.
For one reason or another the slide either unlocked under high pressure (such as the case for a double/overcharge) or fired while out of battery.

A double charge in a glock will also cause the slide to unlock under pressure, as it is recoil operated, just like the C9.
The locked breach does not matter then the projectile generates the recoil necessary to unlock the slide.

 

[AABEN]

YES he was over charged! It do also look like out of battery could had been a high primer!