View Full Version : AR FAIL at the range...
wetidlerjr
07-30-12, 08:30
Below are pics taken yesterday of a catastrophic failure (kaboom)of an AR at the range of the club I belong to.
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM007.jpg
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM013.jpg
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM015.jpg
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM003.jpg
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM023.jpg
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM033.jpg
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM021.jpg
http://img.photobucket.com/albums/v114/wetidlerjr/Colt%201911/PSA%20AR%20ECC%20o72912/PSA_ARKABOOM005.jpg
PSA M4 16" /Federal XM193 ammo/Approx 500 rds total through this rifle. This happened with the sixth round fired using a MAGPUL mag.
This IS NOT my rifle. No injuries outside of a small cut on the owner's right cheek. One part was thrown about 40-50 feet.
Still amazes me that an AR-15 can go high order and the shooter is barely scratched. Its a testament to the strength of the design.
davidjinks
07-30-12, 08:46
Holy crap! That KB sheared the upper off at the lugs?
I'm glad to shooter wasn't seriously injured. Do you have any information on the LOT number for the ammo? Was it bulk packed or in the box?
Damn.....
wetidlerjr
07-30-12, 09:52
No info on the ammo lot number. It wasn't bulk packed. The owner is contacting PSA and Federal today.
Holy shit, that is intense! Good to hear no was was injured. But DAMN!
WHEW! That's probably the worst KB I've seen!
Strangely I've never heard of PSA.
Glad he's ok. That's out of control........
WHEW! That's probably the worst KB I've seen!
Strangely I've never heard of PSA.
You have; Palmetto State Armory.
Animal_Mother556
07-30-12, 10:17
Strangely I've never heard of PSA.
If that's a joke, it's hilarious...
Amazing amount of force in such a small package, huh?
Looks like that rifle came apart REAL quick.
Brasilnuts
07-30-12, 11:16
I don't smoke, but I think I would also have had a cigarette after that.
Wow, glad the shooter is okay. That is one hell of a KB.
Keep us posted on the situation. I have a ton of boxed Federal XM193 and would love to know the lot number...
Wow........
Glad the shooter is still in one piece after that. I appreciate it when people share these because it serves as a reminder to always wear your 'eyes and ears".
You have; Palmetto State Armory.
Ah. I had no idea they made their own AR but I buy all my ammo from them :D
Wow! Glad the shooter is ok! What do you all think caused this?
SWATcop556
07-30-12, 11:53
Wow! Glad the shooter is ok! What do you all think caused this?
Given the limited info we have I would almost bet the bank that it was an ammo issue.
Holy crap! That KB sheared the upper off at the lugs?
I'm glad to shooter wasn't seriously injured. Do you have any information on the LOT number for the ammo? Was it bulk packed or in the box?
Damn.....
Amazing, like others said ; I am glad the shooter is physically OK. I have never been around a high order kb!, and am glad. Potential for disaster was there, and either luck or rifle design lessened a bad situation.
Please update when you get more info.
JBecker 72
07-30-12, 11:59
Wow, that thing really came apart. Most importantly the shooter is ok. Thanks for sharing.
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Holy crap. Please keep us posted on the cause/diagnosis... I'm fascinated by this one (assuming these were Federal XM193 factory loads).
good gawd...whomever had that on the cheek is VERY lucky.
Did the round before the kaboom exit the muzzle? Is there a bullet in the barrel?
First things first: I am glad that the owner is OK.
Hopefully the owner kept all of the ammunition (and the packaging, if possible). That can all be sent in to Federal and they'll investigate the issue. If it's ammo-related, they'll make it right and replace the rifle.
Magic_Salad0892
07-30-12, 13:14
Ah. I had no idea they made their own AR but I buy all my ammo from them :D
They don't. They are FN guns*, and parts from other makers** with PSA markings.
*As fas as I know. Their barrels have FN markings, and I think their bolts do too, but I haven't seen a PSA/FN bolt in person, yet. My source for that is a friend who called PSA himself and asked about it while I was in the room***.
***He was actually in the back of my car.
**
Definitely not a "FN gun".
FN makes some of the barrels and some of the parts, but not everything.
The lowers are LW Schneider currently, and used to be AeroPrecision. Uppers are Anchor Harvey forgings with an unknown finisher. LPKs used to be all sorts of different makers, but are Schneider currently.
Used to use Wilson barrels, too.
Given the limited info we have I would almost bet the bank that it was an ammo issue.
No question it was ammo related.
I'm not sure why some are suggesting that PSA should be contacted. Not their problem by any stretch... just sayin'.
wetidlerjr
07-30-12, 13:32
No question it was ammo related.
I'm not sure why some are suggesting that PSA should be contacted. Not their problem by any stretch... just sayin'.
No one is "suggesting that PSA should be contacted".
The owner said he would contact PSA and Federal which is HIS prerogative.
Looks like all the force was fed back into the upper receiver. The bolt still looks locked into the barrel extension. Any views of the fired case? Not saying this is the prob, but it looks like the same effect I've seen where a pistol was over charged with some really fast powder and grenaded.
Cincinnatus
07-30-12, 13:48
Can't tell from the pics. Any damage to the lower?
nineteenkilo
07-30-12, 13:49
Did the round before the kaboom exit the muzzle? Is there a bullet in the barrel?
Curious about this myself.....from the amount of back pressure there almost had to be a squib blockage or something similar
Blockage of some sorts, My best bet.. Did the round cycle or remain in chamber? Blockage/explosion from front of shell push shell out. blockage/explosion from rear of shell would leave shell still in chamber. Well thats my thought process at least.
mastiffhound
07-30-12, 14:45
I'm glad to hear everyone is ok. Damn that is scary! I really want to know what happened, as I have a PSA and a ton of Fed xm193! If lot numbers become available please give them out as soon as possible, as I consider this a potentially deadly situation. I really mean it, thank God that the owner is ok! I have never had or seen a kaboom in person and would really never like to either for that matter. Please keep us all updated!
http://www.youtube.com/watch?v=tWygoxV_ApM This kinda reminded me of vid.. Did the operator use the foward assist proir to KaBoom? I wanna say remember hearing about excessive or hard FA use somehow jamming the bullet in chamber in such fasion that blows back or something like that. I dunno...**EDIT: OP said was 6th in string of fire of mag.
Yep thats a nasty one! Glad the shooter is alright. Looks to be classic over pressure /casehead seperation. All the force directed to the rear!
Barrel blocked usually ruptures/bulges the barrel. Was there any barrel bulging?:confused:
http://www.youtube.com/watch?v=tWygoxV_ApM This kinda reminded me of vid.. Did the operator use the foward assist proir to KaBoom? I wanna say remember hearing about excessive or hard FA use somehow jamming the bullet in chamber in such fasion that blows back or something like that. I dunno...
It is called set back, the bullet is pressed back into the case during the loading cycle. It happens every time you cycle a round. However, due either to (or all of the above) harsh loading cycle, excessive amounts of loading or unloading a round or inadequate crimp the amount of bullet set back may become dangerous. It can increase pressures in the weapon to 200%+ normal loads.
It is called set back, the bullet is pressed back into the case during the loading cycle. It happens every time you cycle a round. However, due either to (or all of the above) harsh loading cycle, excessive amounts of loading or unloading a round or inadequate crimp the amount of bullet set back may become dangerous. It can increase pressures in the weapon to 200%+ normal loads.
And you would be wrong! GunnutAF hit the nail on the head.
And you would be wrong! GunnutAF hit the nail on the head.
Cool story bro.
If you bothered reading my post and the post I quoted/was replying to, I was telling lunchbox what the phenomenon he was describing is - not debunking GunnutAF's explanation.
I don't smoke, but I think I would also have had a cigarette after that.
Definitely. Winston's are unharmed, thank God. :D
Glad shooter is OK, definitely would appreciate an update as they are available.
So thankful no one got hurt.
Every time I see one of these makes me glad I not shoot bullpup rifles.
IYAAYASwarrior
07-30-12, 16:12
So thankful no one got hurt.
Every time I see one of these makes me glad I not shoot bullpup rifles.
True statement. If something that catastrophic happened with a Bullpup design I couldnt imagine the damage the shooter would have taken. Glad no one was hurt.
G34
Your vid show a bullet getting stuck in the barrel! The round that the shooter tried to fire just before mag change lodged the bullet in the barrel. He reloaded mag and preceeded to forced a round into the chamber far enough to fire, alass KB!
Hopefully the owner kept all of the ammunition (and the packaging, if possible). That can all be sent in to Federal and they'll investigate the issue. If it's ammo-related, they'll make it right and replace the rifle.
I've always wondered on this. I mean what happens if your rifle KaBooms in your hands, are you SOL or is the ammo manufactuer responsible for it? (assuming ammo related malfunction) I doubt the Firearm manufactuer will do anything.
If they dont take care of it, that is an expensive loss to take.
wetidlerjr
07-30-12, 19:03
I have no further info at this time. I can say we did put a brass rod down the barrel that reached the chamber without restriction. There was no attempt to further disassemble the rifle at the range than what is seen in the pics. I will try to contact the owner later in the week for an update.
I've always wondered on this. I mean what happens if your rifle KaBooms in your hands, are you SOL or is the ammo manufacturer responsible for it? (assuming ammo related malfunction) I doubt the Firearm manufacturer will do anything.
If they dont take care of it, that is an expensive loss to take.
I can't speak for all of the manufacturers but I know that if the ammo and weapon are returned to Federal and they are able to determine that the failure was related to their ammunition, they will replace the weapon. If it's determined that the weapon was at fault, no ammunition was returned, or the ammunition was NOT produced by Federal then the owner (or weapon manufacturer) will be responsible for replacement.
HackerF15E
07-30-12, 22:16
They don't. They are FN guns* with PSA markings.
Definitely not a "FN gun".
FN makes some of the barrels and some of the parts, but not everything.
The lowers are LW Schneider currently, and used to be AeroPrecision. Uppers are Anchor Harvey forgings with an unknown finisher. LPKs used to be all sorts of different makers, but are Schneider currently.
Used to use Wilson barrels, too.
Magic_Salad0892
07-30-12, 22:56
Definitely not a "FN gun".
FN makes some of the barrels and some of the parts, but not everything.
The lowers are LW Schneider currently, and used to be AeroPrecision. Uppers are Anchor Harvey forgings with an unknown finisher. LPKs used to be all sorts of different makers, but are Schneider currently.
Used to use Wilson barrels, too.
That's good info to know. If you can give me a source for that, I'll edit it into my post.
Definitely not a "FN gun".
FN makes some of the barrels and some of the parts, but not everything.
The lowers are LW Schneider currently, and used to be AeroPrecision. Uppers are Anchor Harvey forgings with an unknown finisher. LPKs used to be all sorts of different makers, but are Schneider currently.
Used to use Wilson barrels, too.Im glad someone said something. I have had my feelings hurt by PSA more than a few times. Fool me once shame on you, fool me twice I might have deserved it, fool me thrice DD/BCM enjoys my money from now on..Not sayin that PSA is responsible for this happening. They use a couple of parts here and there, and just because they slap a silk robe on a pig, every one wants to pin a ribbon on it. (Sorry, like I said feelings hurt)
that is definitely the worst ar KB ive seen before.
wear your safety glasses folks!
The_War_Wagon
07-30-12, 23:51
I have no further info at this time. I can say we did put a brass rod down the barrel that reached the chamber without restriction. There was no attempt to further disassemble the rifle at the range than what is seen in the pics. I will try to contact the owner later in the week for an update.
Can a KB blow the same obstruction OUT of the barrel, that CAUSED the KB in the first place? :confused:
Can a KB blow the same obstruction OUT of the barrel, that CAUSED the KB in the first place? :confused:If you look at pics of the damage, all of deformation is at base of barrel, front of BCG.
G34
Your vid show a bullet getting stuck in the barrel! The round that the shooter tried to fire just before mag change lodged the bullet in the barrel. He reloaded mag and preceeded to forced a round into the chamber far enough to fire, alass KB!
Not my video. I quoted a guy who linked to that video and said this.
"Did the operator use the foward assist proir to KaBoom? I wanna say remember hearing about excessive or hard FA use somehow jamming the bullet in chamber in such fasion that blows back or something like that. I dunno..."
I then explained what bullet setback is, which is what he was describing. Please read before you reply. Your analysis of the video was spot on - meanwhile, I wasn't commenting on it.
Not my video. I quoted a guy who linked to that video and said this.
"Did the operator use the foward assist proir to KaBoom? I wanna say remember hearing about excessive or hard FA use somehow jamming the bullet in chamber in such fasion that blows back or something like that. I dunno..."
I then explained what bullet setback is, which is what he was describing. Please read before you reply. Your analysis of the video was spot on - meanwhile, I wasn't commenting on it.Q-balling-Not exactly set back. What happened in that vid in IMO And event i'm refering: If you end up with a squib round the bullet will lodge into the riflings. When you eject the case and chamber the next round it wont go all the way in because it hit the lodged bullet. You can put the cartridge into battery by using your forward assist. Now when you pull the trigger the round "goes off" builds up too much pressure from the two bullets and boom.
This the second KB I have seen on the net in as many months and noted both had the BC blow out. Granted ammo seems suspect in this incedent but could there be a BC problem out there too. The other KB was a Colt.
This seems to be a really bad KB and looks like more than set back. Damn was that green dot in the case?!!
Has federal issued a recall on any xm193 lots within the last 12 months?
OP, could you get a production date & lot number for us on the ammo he was using? I'd like to check my supply just to be cautious.
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The_War_Wagon
07-31-12, 12:39
Company boilerplate on XM193 - http://www.federalpremium.com/resources/xm193.aspx
No current notices on XM193 - http://www.federalpremium.com/whats_new/safety_notice.aspx
Im glad someone said something. I have had my feelings hurt by PSA more than a few times. Fool me once shame on you, fool me twice I might have deserved it, fool me thrice DD/BCM enjoys my money from now on..Not sayin that PSA is responsible for this happening. They use a couple of parts here and there, and just because they slap a silk robe on a pig, every one wants to pin a ribbon on it. (Sorry, like I said feelings hurt)
;) know how ya feel, it can get pretty confusing across their product line.
My barrel has the FN rollmark on it, but maybe I got lucky :secret:
Pretty tough to see though..
http://i163.photobucket.com/albums/t294/myersma2/Technical%20and%20Parts/barrelmarks-1.jpg
wetidlerjr
07-31-12, 14:13
Has federal issued a recall on any xm193 lots within the last 12 months?
OP, could you get a production date & lot number for us on the ammo he was using? I'd like to check my supply just to be cautious.
I have no access to the ammo he used. I will probably contact him later this week and will try to get it.
I have no access to the ammo he used. I will probably contact him later this week and will try to get it.
Understood. Just hoping you might be able to get some some info from the owner.
Sent from my DROID RAZR using Tapatalk 2
The BCG in the pics looks really "dry." Could that have played a role in such a failure or contributed in any way?
... Or does it just look dry due to the blast during failure just cleaning everything off by force?
Never seen anything like that. Hope to never have to witness it, especially first hand.
HackerF15E
07-31-12, 17:21
That's good info to know. If you can give me a source for that, I'll edit it into my post.
All info gathered from PSA company rep postings here and on TOS, in addition to seeing the Anchor Harvey forging mark on a PSA upper I own.
All of it should be easily found on Google.
HackerF15E
07-31-12, 17:23
Im glad someone said something. I have had my feelings hurt by PSA more than a few times. Fool me once shame on you, fool me twice I might have deserved it, fool me thrice DD/BCM enjoys my money from now on..Not sayin that PSA is responsible for this happening. They use a couple of parts here and there, and just because they slap a silk robe on a pig, every one wants to pin a ribbon on it. (Sorry, like I said feelings hurt)
So, who makes each of the parts on a DD or BCM rifle?
I don't see how listing the manufacturers of PSA parts equates to a "silk robe on a pig". They're certainly not under any requirement to identify their suppliers, and in some cases may be specifically prohibited from naming their suppliers. I fail to understand how so many people automatically decide that means their products are crap or questionable.
DD, BCM, Spike's, etc, also do not identify all of their suppliers, and I don't see anyone having a serious crisis about it. Double standard anyone?
HackerF15E
07-31-12, 17:28
;) know how ya feel, it can get pretty confusing across their product line.
My barrel has the FN rollmark on it, but maybe I got lucky :secret:
No luck involved. PSA is open about which products they get from FN, and advertise the rifles with FN barrels openly on their website. IIRC most of their currently offered rifles have FN barrels.
Their 4140 barrels were sourced from Wilson (up until about the end of 2011 IIRC), but I don't think PSA even sells the 4140 barrels anymore.
No luck involved. PSA is open about which products they get from FN, and advertise the rifles with FN barrels openly on their website. IIRC most of their currently offered rifles have FN barrels.
Their 4140 barrels were sourced from Wilson (up until about the end of 2011 IIRC), but I don't think PSA even sells the 4140 barrels anymore.
I realize that. I was joking.
It's clearly listed I agree. There's just a lot of variety to digest. I don't care to keep up anymore...as they're my source for inexpensive lowers and that's about it.
Magic_Salad0892
07-31-12, 17:43
All info gathered from PSA company rep postings here and on TOS, in addition to seeing the Anchor Harvey forging mark on a PSA upper I own.
All of it should be easily found on Google.
Okay. It's getting edited into my post. Thanks.
Wow, never seen that before. Lucky no one was injured.
HackerF15E
07-31-12, 18:10
Okay. It's getting edited into my post. Thanks.
I could have gone the extra mile and found each of those individual threads and posts and gathered links, but I'm too lazy. :D
HackerF15E
So which AR manufactures make all there parts in house? I don't think even Colt does!:D
Alaskapopo
07-31-12, 18:31
Saw some pics that looked simular before when someone accidently used pistol powder in the case while reloading.
Pat
HackerF15E
07-31-12, 18:54
HackerF15E
So which AR manufactures make all there parts in house? I don't think even Colt does!:D
I agree. I'm not one of the people who is all bothered by not knowing where all the parts are made and by whom.
There are a good number of folks who, over the last year or so, have given PSA a bunch of flak for not knowing where their parts are sourced.
My point was that other manufacturers that have the same sourcing and manufacturing practices don't get this same level of scrutiny and criticism.
It is called set back, the bullet is pressed back into the case during the loading cycle. It happens every time you cycle a round. However, due either to (or all of the above) harsh loading cycle, excessive amounts of loading or unloading a round or inadequate crimp the amount of bullet set back may become dangerous. It can increase pressures in the weapon to 200%+ normal loads.
Please cite your source
Please cite your source
This wouldn't be too hard to check. Measure a round, chamber it, eject it and then remeasure. I bet it won't change. I do believe that my reloading manual says something about pressure increasing with deeper seating of the bullet in the case but I think it would have to be seriously jammed into the case like almost completely.
So, who makes each of the parts on a DD or BCM rifle?
I don't see how listing the manufacturers of PSA parts equates to a "silk robe on a pig". They're certainly not under any requirement to identify their suppliers, and in some cases may be specifically prohibited from naming their suppliers. I fail to understand how so many people automatically decide that means their products are crap or questionable.
DD, BCM, Spike's, etc, also do not identify all of their suppliers, and I don't see anyone having a serious crisis about it. Double standard anyone?Well I was talking about the three times (not 1 nor2 but 3 TIMES, You step up to the plate in base ball swing three times and miss..Your out buddy) that had gotten screwed by them..The other part was a joke at their expence:D
This wouldn't be too hard to check. Measure a round, chamber it, eject it and then remeasure. I bet it won't change. I do believe that my reloading manual says something about pressure increasing with deeper seating of the bullet in the case but I think it would have to be seriously jammed into the case like almost completely.
The information given by G34 is incorrect. Seating the bullet deeper doesn't increase pressure, in fact, it usually decreases pressure, or at least gives a shallower pressure spike as it increases leade. I had some 22-250 ammo that exhibited high pressure signs, including flattened primers and a stuck bolt. I seated the bullets deeper and brought the pressure back to normal.
The bolt slamming a fresh round into the chamber does not cause the bullet to set back in the case. In fact, if the neck tension is too low, quite the opposite. It will let the bullet jump forward. If it jumps forward enough to jam into the rifling, it will cause a spike in pressure which could lead to a destroyed rifle.
Rounds can be battered during recoil while in the magazine. If neck tension is inadequate, this can result in the bullets being set back in the case. With the 5.56, the tension would have to be real low for any significant change in the overall length.
The carrier of the rifle in question was destroyed because the barrel extension had a catastrophic failure and could not contain the bolt being shoved violently backward. The upper receiver was destroyed by the barrel extension coming apart and probably the violent movement of the BCG as well
I have had a round slam into the receiver below the feed ramp and push tbe bullet into the case so far that barely any of it was protruding beyond the case mouth. I'm not sure what would have happened if I would have tried to fire that round bbecause I tthrew it out. I doubt it would have exploded my upper though. I dont think that a cartridge could be loaded long enough to cause so much pressure to destroy a upper due to the limitations of the length of the magazine. Bolt actions are a differ t story because they can be loaded one at a time directly into the chamber. When I reload for my bolt guns I load them .010 off the lands.
The information given by G34 is incorrect. Seating the bullet deeper doesn't increase pressure, in fact, it usually decreases pressure, or at least gives a shallower pressure spike as it increases leade. I had some 22-250 ammo that exhibited high pressure signs, including flattened primers and a stuck bolt. I seated the bullets deeper and brought the pressure back to normal.
The bolt slamming a fresh round into the chamber does not cause the bullet to set back in the case. In fact, if the neck tension is too low, quite the opposite. It will let the bullet jump forward. If it jumps forward enough to jam into the rifling, it will cause a spike in pressure which could lead to a destroyed rifle.
Rounds can be battered during recoil while in the magazine. If neck tension is inadequate, this can result in the bullets being set back in the case. With the 5.56, the tension would have to be real low for any significant change in the overall length.
The carrier of the rifle in question was destroyed because the barrel extension had a catastrophic failure and could not contain the bolt being shoved violently backward. The upper receiver was destroyed by the barrel extension coming apart and probably the violent movement of the BCG as wellOAL decrease can increase pressure depending on round and charge. A small cal with limited case capacity add in decreased OAL pressure can go up. Not so much with large case cap. and low charge. As far as 22-250 incedent I belive you had bullet touching land and grooves which also can raise press., by decreesing OAL backing of lands it allowed normal pressure funtions.IMO
OAL decrease can increase pressure depending on round and charge. A small cal with limited case capacity add in decreased OAL pressure can go up. Not so much with large case cap. and low charge. As far as 22-250 incedent I belive you had bullet touching land and grooves which also can raise press., by decreesing OAL backing of lands it allowed normal pressure funtions.IMOSource http://www.exteriorballistics.com/reloadbasics/seating.cfm Its in a bunch of other reloadin manuals too
Deep seating is a concern with pistol powders with a fast burn rate such as Unique when maximum loads are used, especially with heavier bullets. Keep in mind however, that full wad cutters (which are used with mild loads) are seated so deep that the front of the bullet is even with the case mouth.
With deeper seating, case capacity IS reduced- temporarily. Once the primer is ignited the bullet is pushed forward again, returning case capacity to normal. This is different than using cases with thicker walls as their capacity stays smaller.
Notice that Sierra issues a warning about reduced case capacity from deep seating possibly raising pressures without showing any test data, referring to any tests that have been made or making any claims about raising pressures as much as 200%. It also goes on to say that seating depth is important to reliable functioning.
This is not to say I claim it's safe to fire rounds that have had bullets shoved completely into the case. But I do know from years of reloading that seating a bullet deeper has never given me signs of excessive pressure, even with max loads while I had to be very careful about seating the bullets out
In the case of the 22-250, the excessive pressure signs were due to the bullets being pushed into the rifling when chambered. Seating them deeper got them off the rifling and reduced pressures, illustrating my point perfectly.
The bottom line is that if the kaboom is due to a change in seating depth, it's because the bullet jumped the case during chambering, not because the bullet was pushed back while in the magazine. Any feed problems resulting in shoving a bullet back in the case usually causes the cartridge to get jammed in the rifle and causing a malfunction
fail wagon
08-02-12, 01:25
that dude is so lucky
AZSUNDEVIL
08-02-12, 23:15
This is a little disconcerting considering that XM193 is all I shoot. I'll be watching this thread for updates.
Suwannee Tim
08-03-12, 17:46
The information given by G34 is incorrect........
I have reloaded for more years than most of you are old. I have reloaded more rounds than most of you put together. MistWolf is correct. G34 is incorrect. In addition to the effect described by MistWolf, seating a bullet deeper reduces interstitial volume which is the volume through which flame propagates. A reduction of this volume reduces the initial powder burn rate which reduces pressure. I have reloaded 458 Winchester magnum and 460 Weatherby magnum with a degree of powder compression that boggles the mind. The more compression the lower the pressure.
I have reloaded for more years than most of you are old. I have reloaded more rounds than most of you put together. MistWolf is correct. G34 is incorrect.
Telling someone the bullet sitting on the powder is reducing pressure is the worst bit of technical misinformation I have heard in a long time. It may be true for some cases and powders, but not all and that is a well documented fact. Hirternberger did a study where setback of 1/10th of an inch in .40 S&W rounds produced a 100% increase in pressure. That is above a proof load.
As a side note, I am not/was not saying that is what caused this explosion, I was replying to a poster who was describing bullet setback but couldn't quite kick out the words "bullet setback".
Alaskapopo
08-03-12, 18:09
Telling someone the bullet sitting on the powder is reducing pressure is the worst bit of technical misinformation I have heard in a long time. It may be true for some cases and powders, but not all and that is a well documented fact. Hirternberger did a study where setback of 1/10th of an inch in .40 S&W rounds produced a 100% increase in pressure. That is above a proof load.
As a side note, I am not/was not saying that is what caused this explosion, I was replying to a poster who was describing bullet setback but couldn't quite kick out the words "bullet setback".
Rifle rounds behave a bit differently on this is my understanding because when the round drops in to the case the powder comes up over the base of the bullet. Its not direct compression like in a straight wall pistol case. Not sure of the internal ballistics but I have been told with rifles the bullets getting pushed back into the case actually reduced pressure.
I had a bit of an embarrasing issue recently with my reloads that I have not fully figured out yet. I loaded some 77 grain Sierra match for my room mate with 24 grains of N140 and it shot fine in his Noveske and its been fine in my AR's its under a max load. Now fast foward to the other week and he tries it out in his MSAR and it pulls the case apart and bends his extractor. I pulled some of the rounds and they all were in spec on the powder charge. I owe my roommate a new extractor as well.
Pat
Rifle rounds behave a bit differently on this is my understanding because when the round drops in to the case the powder comes up over the base of the bullet. Its not direct compression like in a straight wall pistol case. Not sure of the internal ballistics but I have been told with rifles the bullets getting pushed back into the case actually reduced pressure.
Pat
Seems like it can go either way with rifles. From Lunchbox's source
"This is especially true if you are loading for maximum accuracy, and need to adjust the seating depth to match the throat of your particular rifle. This is fine, but bear in mind that deeper seating reduces the capacity of the case, which in turn raises pressures. Going the other way, seating a bullet out to the point that it actually jams into the rifling will also raise pressures. If you vary the seating depth from the length listed in the manual, the charge weights will need to be adjusted accordingly."
Seems like to get the right pressure curve, you may need to straddle a fine line between too deep and not deep enough. I don't reload rifle rounds (as you said, there is a difference), but know in handguns it is bad, bad, bad.
Alaskapopo
08-03-12, 18:15
Seems like it can go either way with rifles. From Lunchbox's source
"This is especially true if you are loading for maximum accuracy, and need to adjust the seating depth to match the throat of your particular rifle. This is fine, but bear in mind that deeper seating reduces the capacity of the case, which in turn raises pressures. Going the other way, seating a bullet out to the point that it actually jams into the rifling will also raise pressures. If you vary the seating depth from the length listed in the manual, the charge weights will need to be adjusted accordingly."
Seems like to get the right pressure curve, you may need to straddle a fine line between too deep and not deep enough. I don't reload rifle rounds (as you said, there is a difference), but know in handguns it is bad, bad, bad.
I agree being one that swore off the .40sw for almost 8 years because of a few KB's I had reloading for it when the cartridge first came out. 1 was a crimping issue allowing the bullet to go back into the case that caused it.
I agree being one that swore off the .40sw for almost 8 years because of a few KB's I had reloading for it when the cartridge first came out. 1 was a crimping issue allowing the bullet to go back into the case that caused it.
KB is on a long list of reasons to swear off .40, especially as an LEO which I assume at many departments may require frequent administrative loading/unloading.
Alaskapopo
08-03-12, 18:24
Telling someone the bullet sitting on the powder is reducing pressure is the worst bit of technical misinformation I have heard in a long time. It may be true for some cases and powders, but not all and that is a well documented fact. Hirternberger did a study where setback of 1/10th of an inch in .40 S&W rounds produced a 100% increase in pressure. That is above a proof load.
As a side note, I am not/was not saying that is what caused this explosion, I was replying to a poster who was describing bullet setback but couldn't quite kick out the words "bullet setback".
Yea I own 1 40sw now and its a STI Edge and I load the bullets long for accuracy and less pressure. (long by 10mm length) But thats a fun gun for USPSA and three gun not for carry.
pat
Every time I ever see these pics it makes me think I have had this kinda stuff happen with rimfire but never damaged the gun or me.
Ed
Suwannee Tim
08-03-12, 19:53
Telling someone the bullet sitting on the powder is reducing pressure is the worst bit of technical misinformation I have heard in a long time. It may be true for some cases and powders, but not all and that is a well documented fact. Hirternberger did a study where setback of 1/10th of an inch in .40 S&W rounds produced a 100% increase in pressure......
The situation with the 40 S&W is different in that the loading density of such is typically 70 to 80% and seating the bullet deeper significantly increases loading density without reducing interstitial volume. At typical pistol loading densities flame propagation occurs in a turbulent environment unconstrained by powder compression that is, the powder grains ignite almost simultaneously. This is true all the more so as pistol cartridges are shorter than rifle cartridges. 5.56 mm will typically have a loading density of 92% to 105%. With these loading densities the flame propagation is in the interstices with no turbulent flow of powder grains. Reducing interstitial volume reduces flame propagation rates and thus pressure.
Telling someone the bullet sitting on the powder is reducing pressure is the worst bit of technical misinformation I have heard in a long time. It may be true for some cases and powders, but not all and that is a well documented fact. Hirternberger did a study where setback of 1/10th of an inch in .40 S&W rounds produced a 100% increase in pressure. That is above a proof load.
As a side note, I am not/was not saying that is what caused this explosion, I was replying to a poster who was describing bullet setback but couldn't quite kick out the words "bullet setback".
Keep in mind a rifle case with rifle powder is a different situation than a 40 S&W case with pistol powder, a cartridge known for it's unusually fast pressure spike
KB is on a long list of reasons to swear off .40, especially as an LEO which I assume at many departments may require frequent administrative loading/unloading.
I was paranoid getting into .40 S&W reloading, so I used the G-Rx die, and carefully checked every step with a calipers.
I am now making my own reloads using Hornady 180 FMJ bullets that I have personally tested by chambering and unchambering 40 times. The round shortened by a grand total, all said and done, by 0.002"; I stopped because I was bored of it, and it was looking pretty beat up in general.
My powder charge is 0.2 grains above minimum (of a nice bulky powder that nearly overflows if double charged) and matches factory 180 HST velocity; chronographed, and functions 100% in my G23.
It can be done. :)
Also, I'm very interested to see what pans out in this thread, I'm sitting on some XM193.
David_USAF
08-04-12, 18:48
WOW, that is insane. Glad the shooter is ok.
Glad the shooter is OK. Please keep us updated on any new info.
Well I put 1,000 of xm193 as did 10 other people in a carbine class today. Im pretty sure that if was a bullet spec problem it was isolated unit and not a whole lot# problem, that and no other reported cases on net have popped up..
Suwannee Tim
08-06-12, 15:02
In the early days of the 458 Winchester magnum Winchester loaded a ball powder and compressed it so severely that there was no interstitial space. Oddly enough they worked in Winchester's labs but in the field they failed. Finn Aagaard wrote that he personally saw a 458 bullet bounce off a buffalo, that is, he saw the bullet in flight then saw it hit and bounce right off. I have personally loaded 300 Winchester magnums with old H870 powder and increased the load from 70 grains all the way up to 86 grains behind a 180 with no evident increase in pressure judging by the case head expansion or primer appearance. Bruce Hodgdon told me that the increase in pressure due to the increase in powder was cancelled out by the reduced burn rate due to lower interstitial volume. The velocity did increase. Some reloaders have manipulated interstitial space and thus burn rate by adding a volume filler to the load, cream of wheat was one popular filler.
man thats scary.
would it make sense to wear like a lower face mask and gloves along with your safety glasses and ear protection at the range?
I don't smoke, but I think I would also have had a cigarette after that.
I'd have a cigarette, buy a lotto ticket, and find the most attractive woman I could and ask her to have sex with me after that.
Anyway OP glad the shooter is ok. Looking forward to see some updates on it down the road.
This the second KB I have seen on the net in as many months and noted both had the BC blow out.
The bolt carrier does not see any pressure from the cartridge firing normally.
This is typical of an AR KB, at the higher end of damage. It looks like a case failure caused by excess pressure. The pressure vents under the extractor and often splits the bolt carrier. Note the brass vapor deposits on the bolt and carrier.
Todd.K
Agreed but did the case fail by simple over pressure or obstruction. Cases fail we all know that. But the amount of damage to the rifle tends to indicate either a severe over pressure or Obstruction.:) I'd love to see the case- or whats left of it.
Todd.K
Agreed but did the case fail by simple over pressure or obstruction. Cases fail we all know that. But the amount of damage to the rifle tends to indicate either a severe over pressure or Obstruction.:) I'd love to see the case- or whats left of it.you can see where the gas found an opening and all the pressure escaped from that point of the most damage. If the gas is being released from a closed high-pressure vessel. Subsequently, the mass flow rate will decrease during the discharge as the source vessel empties and the pressure in the vessel decreases. Just dont think incipient case head separation is the case here.
wetidlerjr
08-07-12, 04:13
I have contacted the owner of this rifle to try to get more info but he has not replied. I will post any new info when and if I get it.
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