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Discussion Starter · #1 ·
Calling all experts. I blew up my Hakim today--cracked the stock, blew out the bottom of original 10 round mag and I peppered my face which was no big deal since I was wearing safety glasses. I bought this one years ago and have never shot it. It blew up on the first round. I was using 1940's Greek ammo, which I've used in other 8mm's without any issues if I'm remembering correctly. So is this a headspace issue or weak brass or ??? I think case ruptures are normally somewhat jagged whereas this rupture is where the extractor normally seats. Note the appearance of the brass--it was not "scratched" like this before firing. Your thoughts?
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Case head failure gives you 50,000psi right into the breech. My Hakim did the same thing with Steel Case German ammo. That ammo lost the whole case head on ignition. It was one round of WW2 German Steel case mixed in with the 1960s ammo I thought I was shooting. Wrecked my Mag, my extractor, my stock and rear sight slide.

I fixed my stock with Super Glue and it is still holding and shooting now some 18 years later.
 

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Glad to hear YOU didn't sustain much damage! It could have been a LOT worse!

That case failure is pretty much JUST ahead of the rim!

Lots of questions!

I am not used to seeing the brass that thin that far back on the case. You do have an unsupported bit of case in the chamber at the extractor cutout on the Hakim, which is usually ok because the case back that far is normally solid brass. Could there have been a crack in the case from a bad drawing process? Do any of your other cases look 'funny' there?

Can you tell how far up the web in the bottom of the case extends?

Were they trying to save some money on material with this brass and made something like the old balloon head cases?

If any other cases look funny, you may want to get a dye penetrant test kit and check the cases out for cracks.

It might be worth breaking down a couple more rounds and cutting them open to see if they all have thin heads and/or thin case walls, or if this was an aberration. If they ARE thin, I would DEFINITELY relegate this stuff to bolt rifles.
 

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Wow, Glad your still intact. I believe that I'd save that ammo for the Bolt Guns. Just a Guess but what about the possibility of a Dirty or Rough Chamber causing an out of Battery Failure? That or like you mentioned maybe a Headspace issue.
 

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A rough chamber could very have been a contributing factor, as well as an improper gas setting, and aged/brittle brass. As you probably know, the Hakim has a very violent gas system that extracts spent brass with enough velocity to send them over 30 feet away. The bolt and carrier are fairly heavy, and once they start moving rearward, there’s not much that will stop them. A dirty chamber, along with a high gas setting, would have caused the brass to stick in the chamber, causing extra-ordinary stresses on the case to extract it. With all that yanking at the unsupported extractor site, the brass could have been stretched to the point of failure.
Most of the time,the chamber has rust or pitting that causes hard extractions---the scratches on your brass look like rust in the chamber, but it could be anything. Try spinning a .410 brass brush chucked in a drill (dipped with solvent). That should get most of the roughness out, along with any other gunk that might be caked in there. If you intend on using the Greek in a Hakim again, inspect them all very carefully, and only load and fire one at a time for the first few shots – inspecting each fired case carefully for signs of weakness. Old cases seem to corrode from the inside out, so be careful. Also, make sure you start out with the gas adjusted to the lowest setting, which is about the 8:00 position.

Sorry about the loss of your Hakim.
TOM
 

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Discussion Starter · #10 ·
Thanks for all of the responses. When I bought the Hakim years ago I guess the guy had cleaned it the night before because I wiped off alot of rust-colored wetness (which I assumed was bore cleaner with rust in it). I checked the barrel for an obstruction before shooting (for the first time, for me), but I didn't look closely at the chamber. My bad.

Ron--I can't answer all of your questions because I don't understand all of them but I will check for solid brass depth at the bottom.

Dirty (rust) bore plus violent extraction seems like the most likely explanation. However, I don't know if this explains why the primer would blow out. Seems like a case rupture on the side would allow gas/pressure escape but why would this cause the primer to blow out? FYI the gas valve was at 7:00.

Last thought: the bullet went about where I would have expected (at a 25 yard target). Does this fact change anything? Thanks.
 

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Thanks for all of the responses. When I bought the Hakim years ago I guess the guy had cleaned it the night before because I wiped off alot of rust-colored wetness (which I assumed was bore cleaner with rust in it). I checked the barrel for an obstruction before shooting (for the first time, for me), but I didn't look closely at the chamber. My bad.

Ron--I can't answer all of your questions because I don't understand all of them but I will check for solid brass depth at the bottom.

Dirty (rust) bore plus violent extraction seems like the most likely explanation. However, I don't know if this explains why the primer would blow out. Seems like a case rupture on the side would allow gas/pressure escape but why would this cause the primer to blow out? FYI the gas valve was at 7:00.

Last thought: the bullet went about where I would have expected (at a 25 yard target). Does this fact change anything? Thanks.
Your case ruptured, it was not "violently extracted". Your Hakim bolt is not designed to pull out a case that still has 50,000psi holding it in the chamber. If so....you would blow out your mag and stock on Every shot. Your rusty bore may have contributed to the case failure/primer blowout by raising chamber pressure but I don't see where that rim of the round suffered anything "violent"...the case just BLEW out in the unsupported area above the rim. It is not uncommon for the primer to leave in all that MALESTROM of gas that resulted in that area.
 

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Ron--I can't answer all of your questions because I don't understand all of them but I will check for solid brass depth at the bottom.
That was pretty much the extent of what I was asking.

Many early cartridges (late 1800's-early-to -mid 1900's) were designed with very thin webs of brass at the rear of the case. Typically, they were so thin that the base of the primer pocket created a very visible hump in the inside base of the brass.

The explanation for the name 'ballooon head' is likely from the fact that the powder space sort of 'ballooned' around the primer pocket.

Many reloading manuals have statements in them that balloon head cases should never be reloaded because of their weakness and tendency to fail.

The shiny ring on the back end of your case where typically you see the rearmost expansion from the brass case body to the chamber wall looks just a bit further back than normal on this case to me, leading me to wonder about the thickness of the base of the case.

If some manufacturer was looking at scrimping on materials to save a bit of money or as a wartime expedient to conserve scarce resources they might look to minimizing the amount of brass in the case base as a viable possibility.
 

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Your case ruptured, it was not "violently extracted". Your Hakim bolt is not designed to pull out a case that still has 50,000psi holding it in the chamber. If so....you would blow out your mag and stock on Every shot. Your rusty bore may have contributed to the case failure/primer blowout by raising chamber pressure but I don't see where that rim of the round suffered anything "violent"...the case just BLEW out in the unsupported area above the rim. It is not uncommon for the primer to leave in all that MALESTROM of gas that resulted in that area.
I concur with this. It looks like a typical "Glock .40 kaboom" pic, where the case head just wasn't supported. Either the case was flawed/corroded, or it wasn't fully seated in the chamber.
1. Repair your gun!
2. Clean the chamber and make sure bullets seat in and out easily (by hand, and don't crush your thumb with the bolt!)
3. Open up a couple of those cartridges and see what the brass looks like on the inside (corrosion, etc). If you don't have the tools, send me a couple and I'll do it for you. (see my 8mm teardown on this forum).

55_grain
 

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Had a friend of mine who had one of these, he locked the bolt open, loaded the magazine, then dropped a loose round in the chamber, released the bolt, it stripped off a round as it was closing, it went into the already chambered round and set it off, blowed his rifle apart just like yours, he also wasn't hurt, but ruined his rifle.
 

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Had a friend of mine who had one of these, he locked the bolt open, loaded the magazine, then dropped a loose round in the chamber, released the bolt, it stripped off a round as it was closing, it went into the already chambered round and set it off, blowed his rifle apart just like yours, he also wasn't hurt, but ruined his rifle.
Ouch. But I suppose you could do that with any semi-auto, couldn't you? The Hakim might be a little easier since the bolt closing is so "enthusiastic".
 

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Ammolab,
I understand what you are saying, the case head did rupture, and a weak case (due to age or manufacturing defect) is a very probable cause. And (of course) I also agree that the Hakim is not designed to extract the shell with pressure in the chamber, BUT, this does happen—and has destroyed several semi-auto’s – Hakims seem to be especially prone to this.
The Hakim was designed to use ammo with a specific pressure curve. Although it has an adjustable gas system, its range is fairly limited. Even on its lowest setting, it still slings brass over 20 feet with many types of ammo. The systems limit is evident when trying to use Turk ammo. When Turk first came out, I tried to get it to work in several of my Hakims. All but one of my rifles would rip the rims off the case at the extractor (usually blowing out the primer in the process), leaving the case in the chamber no matter what the gas setting was on. The ‘stuck’ case could be extracted with a screw-driver with almost no effort. This tells me that the case was still expanded against the chamber walls when the extraction started. One of my Hakims works fine with Turk – which simply implies that every rifle is as individual and preferential as people are. Some Hakim owners have filed a few extra notches in their Hakim’s gas block to give them a little lower gas setting so that they could use the ‘cheap’ Turk. The consensus is that Turk ammo was loaded for long barreled bolt-action Mauser’s with a slow-burning powder. The slow-burning powder kept more pressure on the bullet throughout its movement down the barrel, giving it a higher velocity without more pressure – in other words, it kept higher pressure against the bullet longer than ammo loaded with fast-burning powder. The problem with this in a Hakim is that the pressure is still too high when the bullet passes the gas port, sending more gas pressure down the gas tube than the design calls for – thus, causing an extraction attempt before the pressure has dropped to a safe level. Most auto-loaders would simply fail to cycle, or their extractor would snap free from the shell, but the Hakim’s beefy extractor and heavy bolt system will usually just rip the rims off the brass (if your lucky – or cause a rupture if your not).
Also, I’m sure 50,000 PSI is not what would be in the chamber during extraction. I’m not sure what residual pressure is needed to cause a case to remain ‘gripped’ against the wall, but it could be as low as 2,000 – 3,000 (or lower). Even with a lower pressure, a case rupture could still be devastating. It’s not really the pressure, but it’s the potential volume of gasses that remain that could raise havoc. Think of a bicycle tire and a tractor-trailer tire—both filled to 60 PSI. If the bicycle tire popped, it might sound like a firecracker, but, if you have ever heard a tractor-trailer tire blow, you know they sound like a cannon going off. Same pressure than the bicycle tire, but vastly more volume.
My point in all this is that a dirty chamber, coupled with 60-year old ammo, coupled with a gas setting set too high for the ammo, could have caused a particular case to rupture in a Hakim that otherwise might not have ruptured if it were fired in a Mauser bolt-gun.
I have also heard that ‘40’s Greek is sometimes re-packed with several different head-stamps, which can increase the difficulty in placing blame on a particular ammo year / lot. I know several people report good results with Greek in semi-autos, but I’d bet – considering its age – that it was likely loaded with slow-burning powder for bolt-guns of the era….

Just a friendly debate

TOM
 

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Tom: Roger all that for sure. But in this case the Rim of the round is not even BENT. No way you can RIP the thick base of a sound, stuck case open without bending the thin rim of the round in question.
That round wasn't streched open or pulled open. I have been behind a Hakim that had a case rupture. I also have seen many Hakim "violent extractions"...quite different from a rupture as they pull the rim right off the case andor break the darn extractor. In this case I still feel the base of that round failed @ HIGH pressure.
 

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After looking at the pic’s again, I see what you mean. I do see extractor marks, almost like the extractor snapped free from the case. So the case ruptured, blowing the carrier and bolt back at the breach, instead of cycling the action via the gas tube?

CandRNut, was the action locked open, or did you have to prythe bolt open?
 

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Discussion Starter · #19 ·
Thanks to all of you as you teach me and others the details which help with safety.

CandRNut, was the action locked open, or did you have to prythe bolt open?
My terminology might not be correct but the entire "bolt carrier" (the housing for the firing pin/extractor and the carrier to which it fits in) was somewhat stuck in the outer cover--the cover that has the square bar "charging handle" on it. I had to remove the rear safety and slide the entire piece off the back to separate the pieces. This will make no sense to anyone who doesn't know a Hakim!

Getting back to your question, all pieces were stuck together and slid as far reward as possible (up next to the rear safety). I did not have to pry the bolt open. Since the bullet did go downrange I can only guess that I had pressure from both the rupture and (slightly later?) from the gas tube as well. Bystanders didn't even know that it had blown up. They'd never seen a Hakim and just thought that violent recoil shook the mag apart. They did say that a large fireball came out the end, easily seen during the day, even with the original muzzle break attached.

I did have to use a Mauser cleaning rod and a hammer to remove the stuck shell. Also note that the rupture occured only in the unsupported area (upper right hand corner) where the extractor grabs.

Concerning the Greek ammo, it has no headstamp whatsoever so I'm relying on the text on the box (in English so it must be a repackage?) which shows the 1940 date. I vaguely recall that this was supposed to be pretty good ammo so I'm bummed that the quality may not be what I had first thought.
 
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