AR-15 failure

TN Hillbilly · October 12, 2009, 01:35 PM

I wanted to put this on here for my brother in-law. He was firing his custom built AR-15 at the range when it suddenly quit firing. When he went to cycle the bolt it was frozen shut and noticed the upper receiver was budged out. This morning he took his rifle back to the shop that built the rifle and they took it apart. What they found was a split case and a extra primer in the gun. They are thinking the round fired before lost its primer and when the rifle cycled it chamber the next round but the primer kept the bolt from closing all the way, the round fired and split the case (not enough support in the throat). He was using factory new 5.56, 55 gr, brass case (he believes possibly WW box, mil spec but has to check). The failure happened on his 2nd 30 round mag. Anyone heard of this before?

**Unclenick** · October 12, 2009, 02:03 PM

New one on me, but the first primer coming out suggests and over-pressure round or a slamfire. The former would lose the primer because the the case head expanded. The second because the pressure would not re-seat it. A third possibility would be the second primer was dropped into the case with the powder at the factory, accelerating powder burn when it went off.

I once found a once-fired LC case from a Camp Perry match that weighed 35 grains too much. Looked inside and saw a dark mass on the bottom. Loosened it with a dental pick. It was a chunk of lead bullet core metal flattened by the pressure. So, weird stuff happens, even in commercially loaded ammo.

TN Hillbilly · October 12, 2009, 02:54 PM

Well the mystery gets better. My b in-law called and said the ammo he was shooting was not WW box but Ultramax reloaded ammo, LC cases. Probably over charged causing the primer to pop out. I don't know if I could trust someone elses reloads but mine. I know Georgia Arms sells a large amount of ammo with reloaded cases, I guess it could happen with any ammo.

**Unclenick** · October 12, 2009, 05:28 PM

I'd guess you just solved the mystery. Just from the name, I would suppose they might be hot loads for bolt guns, but not intended for a gas gun. Sorry your BIL had to learn the hard way about that.

I'm with you on reloads. I've seen some pretty pathetic and also some very hot commercial ones. Hot ones from a guy without a pressure barrel developing them at his own range in a gun that might have a loose chamber so the pressure is lower, is a problem waiting to happen. Then they get put not only into a gas gun, but one that is a custom build, which likely has a tight chamber.

It's also possible that first case was out of spec before it was reloaded, too! Possibly from having that same hot load in them before. No clue what Ultramax's inspection standards are?

Farmland · October 12, 2009, 07:01 PM

Interesting that just about every AR 15 that I read about blowing up was due to reloads. The number one reason an overcharged load. There is a nice store on the web complete with photos and lab results that reviews one such case. Though in that case it might have also been due to the use of the wrong powder.

Farmland · October 12, 2009, 07:12 PM

I just thought I would share this with you. it may not be close to what your friend did but it is interesting when it comes to reloading.

http://www.quarterbore.com/ar15m16/ar15kaboom.html

du chicot · October 12, 2009, 08:10 PM

i was thinking about re-loading for my new R-25 in 7mm08 but after seeing this string i guess i should reconsider.

rjrivero · October 12, 2009, 08:36 PM

Quote:

Originally Posted by du chicot

i was thinking about re-loading for my new R-25 in 7mm08 but after seeing this string i guess i should reconsider.

Reloading is a hobby that can not be taken lightly. Done correctly, it is quite safe and economical to do. However, you can't take anything for granted. You have to BE SURE your charges are correct, and you have to make SURE your powders are correct.

It's recklessness that caused that ka-boom. Having unlabeled containers of powder on the bench? That's a disaster waiting to happen. He's quite lucky to have all his parts intact.

TN Hillbilly: That rifle needs to go back to the manufacturer to have a thorough inspection. He probably voided the warranty on it by using reloads, even if he did so un-knowingly. But it needs to be inspected before it is put back into service. Perhaps a CERTIFIED LETTER to the ammunition manufacturer can bring some satisfaction for the cost of inspection, repair or replacement. I wouldn't hold my breath.

Farmland · October 12, 2009, 08:41 PM

Remingtons have been known to just go kaboom for no reason so I wouldn't worry to much about it. Seriously even factories have been known to do the same thing, if you look at the above link their is a story about factory loads being over loaded. The outcome was pretty good the guy got a new rifle for free.

There is nothing wrong with reloading, I only really meant my comment about the AR having more problems because of owners doing incorrect reloading practices. I don't have any facts but it is just my opinion from what I read.

My theory is that because of the increase of a once cheap ammunition there are a lot of new people reloading that are just doing some sloppy work.

In the OP's case it appears that the ammunition was factory re-manufactured.

By all means consider reloading it is safe though you have to pay attention to the details. Thee are far more successful reloaders having a lot of fun and doing it with out any problems.

TN Hillbilly · October 12, 2009, 09:32 PM

This story is better than a soap opera. Well my BIL called this evening and the plot thickens. After pulling all the unfired rounds from his clip he was using when the malfunction happened, all was LC 09 headstamps. Then he proceeds to load his clip with new factory milspec ammo and what do you know, out of the Federal box comes LC 09 headstamps. So he believes he was using Federal the whole time (he thought this in the very beginning but the LC headstamp instead of Federal headstamp confused the issue). I found a thread on the 1911 forum dated 4/09 and AR-15 forum dated 6/09 that mentioned problems with primers blowing out of a AR-15. It went on to say that Federal XM193, 55gr, FMJ ammo was blowing out primers and had 5-6 people with different makes of AR-15 reporting this problem. The shop who built my BIL rifle has asked him to bring 2 boxes so they can do some remote test firing and see if they can duplicate the problem.

du chicot · October 12, 2009, 10:01 PM

Gents
Thanks for the comments. I have been reloading for about a dozen years. Mostly for my 270's but also for '06, 6mm, 45-70, 308, and 348win but have never reloaded anything for a "gas gun". In fact the only thing not in a bolt has been the 348win. I have presumed that if I did not go near the maximum's I should not have anything to worry about. I was just really curious about the "gas guns".

plainsman456 · October 13, 2009, 01:34 PM

Recent shooting with ultamax reloadshas led me to belive that they were trying to save a little powder.After trying new boxes from the same case,the first one wouldn't print 5 or 6 in group at 100 yards.The next box fron the same case did ok 1/2 in groups.When we got back to the shop some rounds were pulled and the powder was weighed.The rounds that did not shoot to spec were 2 or 3 grs lighter than the ones that did well.Seems that something was off when loading orthey were trying to cut back on loads for some other reason.Just what I have seen. Good Luck

Double Naught Spy · October 13, 2009, 06:35 PM

Quote:

This story is better than a soap opera.

You mean to tell me that your BIL blows up a gun and he doesn't know what ammo he was using in his custom built AR15 and moreover, his stories to you have changed twice since the original?

That mule won't pull a ploy.

Farmland · October 13, 2009, 08:29 PM

Prior to reloading I would shoot a variety of factory ammunition and most times it was mix in any given magazine. It would be easy to get confused about which ammunition I was using if my gun went Kaboom. So I find it 100% that his BIL could have been confused on what ammunition he was using.

So in fact this dog does hunt with me.

FrankenMauser · October 13, 2009, 08:51 PM

Quote:

Farmland says: Remingtons have been known to just go kaboom for no reason so I wouldn't worry to much about it.

I don't own a single Remington, but....

Out of respect for the company, and the community on this forum; I think you need to back that statement up with proper supporting statements and source citations.

Farmland · October 13, 2009, 09:03 PM

Read the full paragraph especially the serious part and the full sentence. If you did then any normal person including Remington knows it is humor.

Remingtons have been known to just go kaboom for no reason so I wouldn't worry to much about it. Seriously even factories have been known to do the same thing, if you look at the above link their is a story about factory loads being over loaded. The outcome was pretty good the guy got a new rifle for free.

Please quote the full statement instead of part thus twisting my intent. I only thought CNN did that.

Note the humor and then the exact statement that ANY factory can have problems, which should have translated for you that it includes all factory ammo just not Remington, which is a truthful statement.

However it is a known fact that their 22 gold bullet is a very poor performer in the S&W 15/22 if you care to do a search. The problems have been failure to fire, hang fire, blown cases and a full host of other problems.

Source - http://smith-wessonforum.com/smith-w...p-15-22-a.html

In addition it is a little humor on their recall of the Remington Model 597 HMR Semi - Automatic Rifle chambered for 17 HMR AMMUNITION which can explode, thus the recall.

Remington has been notified by its supplier of 17 HMR ammunition that 17 HMR ammunition is not suitable for use in semi-automatic firearms. The use of this ammunition in a semi-automatic firearm could result in property damage or serious personal injury.

Too bad for owners they do not offer a full refund.

Feel free to check their own web page.

Now do you feel better since my facts were truthful though the actual use was in a humorous joking manner as stated in my original part of that thread. Happy now?

Double Naught Spy · October 13, 2009, 10:20 PM

Quote:

Prior to reloading I would shoot a variety of factory ammunition and most times it was mix in any given magazine. It would be easy to get confused about which ammunition I was using if my gun went Kaboom. So I find it 100% that his BIL could have been confused on what ammunition he was using.

So in fact this dog does hunt with me.

Yes, but how many times is he going to be confused? He has the actual split case but has attributed it to three different things. First it was factory new brass, possibly Winchester. Then it was Ultramax reloads using LC brass. Then it was Lake City XM193 ammo.

No mention was made of mixing ammo types in the magazine. So the story is hokey. You may mix ammo, but that isn't what was described.

Farmland · October 13, 2009, 10:24 PM

Understand your point but I think it may still be possible to be confused after such an event. I certainly know that I would be. In any event something did happen to his rifle. BTW the only time I ever had a similar event it was due to my own reload, though I got out of it with a broken extractor. It was due to an accidental overload. I made an error reading the scale.

TN Hillbilly · October 13, 2009, 10:55 PM

The only reason Ultramax came up was the LC brass. He thought because of the headstamp that it must have been some reloaded ammo left over. He did not know (I did not either) that Federal was using LC brass until he opened a new box of Fed XM193. He also owns more than 1 black rifle with a dozen mags that have ammo in them so he guessed it was WW box when he called me the 1st time (remember the rifle was jammed so he could not get the spent case out of the chamber). Only after he took the rifle back to the shop and unloaded the remaining rounds in the mag did he see the LC headstamp.

Quote:

You mean to tell me that your BIL blows up a gun and he doesn't know what ammo he was using in his custom built AR15

If he paid money out of pocket for a custom AR-15 I would say yes, he would know what ammo he was shooting but this custom gun did not cost him really anything. He made a 1 in a million super deal on a group purchase of 20 rifles. In the group was a Galil rifle (paid $150.00) so he made a trade with the owner of the gun shop for the custom AR and cash. When he went to the range he just grabbed some mags that were already loaded and because he buys ammo whenever he finds a good deal (like most of us) he had no idea what brand of ammo was in the clip. If I owned a custom AR I would not treat it any different as far as ammo goes (I would exclude steel cased and reloads other than mine).

FrankenMauser · October 14, 2009, 01:32 AM

Quote:

Please quote the full statement instead of part thus twisting my intent. I only thought CNN did that.

No. No. No. I gave you a chance to support your claim, and the sentence quoted was the problem.

Quote:

Note the humor and then the exact statement that ANY factory can have problems, which should have translated for you that it includes all factory ammo just not Remington, which is a truthful statement.

Reassess the quoted statement. In the context you presented it, "Remingtons" is easily interpreted to mean their firearms. If you meant ammunition, it should have been specified. The sentence you follow with reads as if it is a different subject, separated from the first.

And... you said they 'go kaboom for no reason'. "No reason" implies complete lack of engineering, and unexpected failure. The instance you are citing was an admitted double charge - a machine error, outside of normal tolerances.

Quote:

However it is a known fact that their 22 gold bullet is a very poor performer in the S&W 15/22 if you care to do a search. The problems have been failure to fire, hang fire, blown cases and a full host of other problems.

Sounds like a S&W problem, to me. One firearm has issues with specific brand of ammunition.... (Sound familiar to anyone else that owns a .22?)

--------------

As for the AR:
Sucks to be him. I would send a carefully worded letter to the ammunition manufacturer, and let them know what happened. I would also take the rifle to an unaffiliated gunsmith, to see if the 'custom built AR' had some shortcuts taken or was improperly assembled.

lmccrock · October 15, 2009, 10:18 AM

Quote:

He did not know (I did not either) that Federal was using LC brass until he opened a new box of Fed XM193.

The difference between Ultramax and Federal using LC cases is that Ultramax is reloading (hopefully) once-fired cases, and Federal is packing and selling overruns and seconds from the Lake City plant, which is operated by Federal's parent, ATK. So, you could say that Federal is LC. Traditionally, Federal's retail XM193 was considered the best bulk ammo, but lately there have been issues. I was not buying any, so I did not pay close attention. To learn more, peruse the AR15.com ammo forum. Seems like "primers falling out" was mentioned.

Lee

thallub · October 15, 2009, 11:13 AM

Quote:

The difference between Ultramax and Federal using LC cases is that Ultramax is reloading (hopefully) once-fired cases, and Federal is packing and selling overruns and seconds from the Lake City plant, which is operated by Federal's parent, ATK.

Exactly.

I have fired military ammo in my .223 guns for over 40 years with no problem. Now there is a definite problem with some LC ammo. Beware of that LC ammo from Federal. Much of it is grade 3 military reject stuff: It does not meet MilSpec and that is why they sell it commercially.

I picked up a lot of this LC brass on a local range. The dates range from 06 to 09. When I started to trim those once fired cases it took a long time for the trimmer to do the job on some of them. So I started looking really close at them. Some were found to have case necks that are .015-.035 longer than MilSpec.

If a case with a long neck is fired in a gun that has a tight chamber, the case neck may be jammed into the throat and all kinds of bad stuff can happen. I've seen evidence of this in some of the cases that were picked up: A couple were missing their primers. Now, primers do not fall out of MilSpec 5.56mm ammo: For one thing they are crimped in to keep them from falling out. They are being blown out due to excessive pressure.

Rich_Lather · October 15, 2009, 12:14 PM

I had a similar problem occur in my AR15. I was shooting Georgia Arms LC reloads and had an overpressure round. It had the extractor extrusion on the case and the primer blew out. The primer blow-out jammed the gun so bad I had to bang a ramrod down the barrel to open the breach.

Georgia Arms .223 does appear to have issues. I would have primers rolling around in the lower assembly after long days at the range shooting that stuff.

You get what you pay for.

thallub · October 15, 2009, 01:26 PM

Blowing a primer out of a once fired case is a big deal. It is an indication of very high pressure for some reason or the other. The primers do not blow out of proof rounds when they are fired in guns having the correct headspace. Those proof rounds make 70,000 psi.

**Unclenick** · October 16, 2009, 01:50 PM

A couple of comments. I followed Lmccrock's links. Very interesting. Two thoughts come to mind. One is that the hardness off the case brass should be checked. Federal cases have a reputation for being soft and not withstanding reloading or higher pressure loads. I would not think the LC headstamp cases would have that problem, because they will have been made at LC, presumably using LC's equipment and methods. That said, ATK is running the plant. Lack of case hardness usually is the result of shortcutting the number of forming steps so the cases don't get all their needed work hardening. See Hatcher's Notebook on this; particularly his high pressure experiments that required he get extra hard case heads which were made by impressing the headstamp extra deeply to get harder brass. Could ATK management have tried to increase efficiency by reducing the number of case forming steps? I haven't seen the mil spec for case forming, so I don't know if it is written to prevent that or not? If ATK did reduce the number of forming steps, it could result in softer brass, and might be a reason for these cases to be refused for LC loading? It would be useful to run a hardness test to compare old LC brass to that from the Federal boxed XM193.

Another point is that the longer NATO spec freebore will reduce peak pressure by allowing more gas bypass. The only measurements of the effect of extra bullet jump I've ever seen were for the .30-06, but in that round it made a 10,000 psi difference to have longer jump. It slows the climb to the pressure peak by allowing more gas to bypass the bullet before the bullet obturates the bore. That delays the pressure peak until the bullet is further down the bore, causing the peak pressure to occur in a larger volume and thus be lower. A 10,000 psi difference is enough to take the primer over the leakage threshold.

The last post in the thread at Lmccrock's second link was of interest. A large fireball is reported from this ammo. That indicates a powder slower than nominal for the bullet weight is in use. If you've followed any of the discussion of secondary pressure spikes resulting from combining slow powder with light bullets, you''ll be aware it distorts the barrel steel enough to make a strain gauge read high but does not produce a significant chamber gas pressure rise, so it doesn't produce a pressure sign on the case. It could, however, allow the normal pressure to widen the case until it sticks badly in the chamber if the timing is right. Scroll down on this page to see some traces that show these spikes.

October 12, 2009, 01:35 PM	#1
TN Hillbilly Member Join Date: March 3, 2009 Posts: 19	AR-15 failure I wanted to put this on here for my brother in-law. He was firing his custom built AR-15 at the range when it suddenly quit firing. When he went to cycle the bolt it was frozen shut and noticed the upper receiver was budged out. This morning he took his rifle back to the shop that built the rifle and they took it apart. What they found was a split case and a extra primer in the gun. They are thinking the round fired before lost its primer and when the rifle cycled it chamber the next round but the primer kept the bolt from closing all the way, the round fired and split the case (not enough support in the throat). He was using factory new 5.56, 55 gr, brass case (he believes possibly WW box, mil spec but has to check). The failure happened on his 2nd 30 round mag. Anyone heard of this before?

October 12, 2009, 02:03 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	New one on me, but the first primer coming out suggests and over-pressure round or a slamfire. The former would lose the primer because the the case head expanded. The second because the pressure would not re-seat it. A third possibility would be the second primer was dropped into the case with the powder at the factory, accelerating powder burn when it went off. I once found a once-fired LC case from a Camp Perry match that weighed 35 grains too much. Looked inside and saw a dark mass on the bottom. Loosened it with a dental pick. It was a chunk of lead bullet core metal flattened by the pressure. So, weird stuff happens, even in commercially loaded ammo. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

October 12, 2009, 05:28 PM	#4
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	I'd guess you just solved the mystery. Just from the name, I would suppose they might be hot loads for bolt guns, but not intended for a gas gun. Sorry your BIL had to learn the hard way about that. I'm with you on reloads. I've seen some pretty pathetic and also some very hot commercial ones. Hot ones from a guy without a pressure barrel developing them at his own range in a gun that might have a loose chamber so the pressure is lower, is a problem waiting to happen. Then they get put not only into a gas gun, but one that is a custom build, which likely has a tight chamber. It's also possible that first case was out of spec before it was reloaded, too! Possibly from having that same hot load in them before. No clue what Ultramax's inspection standards are? __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; October 12, 2009 at 05:34 PM.

October 12, 2009, 08:10 PM	#7
du chicot Junior Member Join Date: October 8, 2009 Posts: 5	so maybe i should reconsider i was thinking about re-loading for my new R-25 in 7mm08 but after seeing this string i guess i should reconsider.

October 12, 2009, 10:01 PM	#11
du chicot Junior Member Join Date: October 8, 2009 Posts: 5	considering reloading for my 7mm08 Gents Thanks for the comments. I have been reloading for about a dozen years. Mostly for my 270's but also for '06, 6mm, 45-70, 308, and 348win but have never reloaded anything for a "gas gun". In fact the only thing not in a bolt has been the 348win. I have presumed that if I did not go near the maximum's I should not have anything to worry about. I was just really curious about the "gas guns".

October 12, 2009, 02:54 PM	#3
TN Hillbilly Member Join Date: March 3, 2009 Posts: 19	Well the mystery gets better. My b in-law called and said the ammo he was shooting was not WW box but Ultramax reloaded ammo, LC cases. Probably over charged causing the primer to pop out. I don't know if I could trust someone elses reloads but mine. I know Georgia Arms sells a large amount of ammo with reloaded cases, I guess it could happen with any ammo.

October 12, 2009, 07:01 PM	#5
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	Interesting that just about every AR 15 that I read about blowing up was due to reloads. The number one reason an overcharged load. There is a nice store on the web complete with photos and lab results that reviews one such case. Though in that case it might have also been due to the use of the wrong powder.

October 12, 2009, 07:12 PM	#6
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	I just thought I would share this with you. it may not be close to what your friend did but it is interesting when it comes to reloading. http://www.quarterbore.com/ar15m16/ar15kaboom.html

October 12, 2009, 08:41 PM	#9
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	Remingtons have been known to just go kaboom for no reason so I wouldn't worry to much about it. Seriously even factories have been known to do the same thing, if you look at the above link their is a story about factory loads being over loaded. The outcome was pretty good the guy got a new rifle for free. There is nothing wrong with reloading, I only really meant my comment about the AR having more problems because of owners doing incorrect reloading practices. I don't have any facts but it is just my opinion from what I read. My theory is that because of the increase of a once cheap ammunition there are a lot of new people reloading that are just doing some sloppy work. In the OP's case it appears that the ammunition was factory re-manufactured. By all means consider reloading it is safe though you have to pay attention to the details. Thee are far more successful reloaders having a lot of fun and doing it with out any problems.

October 12, 2009, 09:32 PM	#10
TN Hillbilly Member Join Date: March 3, 2009 Posts: 19	This story is better than a soap opera. Well my BIL called this evening and the plot thickens. After pulling all the unfired rounds from his clip he was using when the malfunction happened, all was LC 09 headstamps. Then he proceeds to load his clip with new factory milspec ammo and what do you know, out of the Federal box comes LC 09 headstamps. So he believes he was using Federal the whole time (he thought this in the very beginning but the LC headstamp instead of Federal headstamp confused the issue). I found a thread on the 1911 forum dated 4/09 and AR-15 forum dated 6/09 that mentioned problems with primers blowing out of a AR-15. It went on to say that Federal XM193, 55gr, FMJ ammo was blowing out primers and had 5-6 people with different makes of AR-15 reporting this problem. The shop who built my BIL rifle has asked him to bring 2 boxes so they can do some remote test firing and see if they can duplicate the problem.

October 13, 2009, 01:34 PM	#12
plainsman456 Senior Member Join Date: December 31, 2008 Posts: 260	Recent shooting with ultamax reloadshas led me to belive that they were trying to save a little powder.After trying new boxes from the same case,the first one wouldn't print 5 or 6 in group at 100 yards.The next box fron the same case did ok 1/2 in groups.When we got back to the shop some rounds were pulled and the powder was weighed.The rounds that did not shoot to spec were 2 or 3 grs lighter than the ones that did well.Seems that something was off when loading orthey were trying to cut back on loads for some other reason.Just what I have seen. Good Luck

October 13, 2009, 08:29 PM	#14
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	Prior to reloading I would shoot a variety of factory ammunition and most times it was mix in any given magazine. It would be easy to get confused about which ammunition I was using if my gun went Kaboom. So I find it 100% that his BIL could have been confused on what ammunition he was using. So in fact this dog does hunt with me.

October 13, 2009, 09:03 PM	#16
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	Read the full paragraph especially the serious part and the full sentence. If you did then any normal person including Remington knows it is humor. Remingtons have been known to just go kaboom for no reason so I wouldn't worry to much about it. Seriously even factories have been known to do the same thing, if you look at the above link their is a story about factory loads being over loaded. The outcome was pretty good the guy got a new rifle for free. Please quote the full statement instead of part thus twisting my intent. I only thought CNN did that. Note the humor and then the exact statement that ANY factory can have problems, which should have translated for you that it includes all factory ammo just not Remington, which is a truthful statement. However it is a known fact that their 22 gold bullet is a very poor performer in the S&W 15/22 if you care to do a search. The problems have been failure to fire, hang fire, blown cases and a full host of other problems. Source - http://smith-wessonforum.com/smith-w...p-15-22-a.html In addition it is a little humor on their recall of the Remington Model 597 HMR Semi - Automatic Rifle chambered for 17 HMR AMMUNITION which can explode, thus the recall. Remington has been notified by its supplier of 17 HMR ammunition that 17 HMR ammunition is not suitable for use in semi-automatic firearms. The use of this ammunition in a semi-automatic firearm could result in property damage or serious personal injury. Too bad for owners they do not offer a full refund. Feel free to check their own web page. Now do you feel better since my facts were truthful though the actual use was in a humorous joking manner as stated in my original part of that thread. Happy now? Last edited by Farmland; October 13, 2009 at 09:23 PM.

October 13, 2009, 10:24 PM	#18
Farmland Senior Member Join Date: July 5, 2009 Posts: 869	Understand your point but I think it may still be possible to be confused after such an event. I certainly know that I would be. In any event something did happen to his rifle. BTW the only time I ever had a similar event it was due to my own reload, though I got out of it with a broken extractor. It was due to an accidental overload. I made an error reading the scale.

October 15, 2009, 12:14 PM	#23
Rich_Lather Junior Member Join Date: October 14, 2009 Posts: 5	I had a similar problem occur in my AR15. I was shooting Georgia Arms LC reloads and had an overpressure round. It had the extractor extrusion on the case and the primer blew out. The primer blow-out jammed the gun so bad I had to bang a ramrod down the barrel to open the breach. Georgia Arms .223 does appear to have issues. I would have primers rolling around in the lower assembly after long days at the range shooting that stuff. You get what you pay for.

October 15, 2009, 01:26 PM	#24
thallub Senior Member Join Date: November 20, 2007 Location: South Western OK Posts: 3,112	Blowing a primer out of a once fired case is a big deal. It is an indication of very high pressure for some reason or the other. The primers do not blow out of proof rounds when they are fired in guns having the correct headspace. Those proof rounds make 70,000 psi.

October 16, 2009, 01:50 PM	#25
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,063	A couple of comments. I followed Lmccrock's links. Very interesting. Two thoughts come to mind. One is that the hardness off the case brass should be checked. Federal cases have a reputation for being soft and not withstanding reloading or higher pressure loads. I would not think the LC headstamp cases would have that problem, because they will have been made at LC, presumably using LC's equipment and methods. That said, ATK is running the plant. Lack of case hardness usually is the result of shortcutting the number of forming steps so the cases don't get all their needed work hardening. See Hatcher's Notebook on this; particularly his high pressure experiments that required he get extra hard case heads which were made by impressing the headstamp extra deeply to get harder brass. Could ATK management have tried to increase efficiency by reducing the number of case forming steps? I haven't seen the mil spec for case forming, so I don't know if it is written to prevent that or not? If ATK did reduce the number of forming steps, it could result in softer brass, and might be a reason for these cases to be refused for LC loading? It would be useful to run a hardness test to compare old LC brass to that from the Federal boxed XM193. Another point is that the longer NATO spec freebore will reduce peak pressure by allowing more gas bypass. The only measurements of the effect of extra bullet jump I've ever seen were for the .30-06, but in that round it made a 10,000 psi difference to have longer jump. It slows the climb to the pressure peak by allowing more gas to bypass the bullet before the bullet obturates the bore. That delays the pressure peak until the bullet is further down the bore, causing the peak pressure to occur in a larger volume and thus be lower. A 10,000 psi difference is enough to take the primer over the leakage threshold. The last post in the thread at Lmccrock's second link was of interest. A large fireball is reported from this ammo. That indicates a powder slower than nominal for the bullet weight is in use. If you've followed any of the discussion of secondary pressure spikes resulting from combining slow powder with light bullets, you''ll be aware it distorts the barrel steel enough to make a strain gauge read high but does not produce a significant chamber gas pressure rise, so it doesn't produce a pressure sign on the case. It could, however, allow the normal pressure to widen the case until it sticks badly in the chamber if the timing is right. Scroll down on this page to see some traces that show these spikes. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle Last edited by Unclenick; October 16, 2009 at 01:56 PM.