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Posted: 8/16/2009 12:22:51 PM EDT
| I'm sure you've all seen the video by now. But my question is, what exactly makes an AR blow up? Is it the rifle itself? Or ammo used? Could some experts way in on this please and educate a noob. Thanks! |
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Actually, I think it is more possibly an undercharged round. There is not much space left in a 5.56 case to extremely overcharge it, so the theory is that an undercharged round whose powder level is low enough that the primer ignites a large area of powder initiates a detonation causing a kB!.
And squibs of course. |
| I agree under charged. If you have a malfunction (and circumstance permits) always check the barrel is not obstructed. Especially when using reloads. Spending 7 years working on a hand gun range I never expirienced a blow up that did not involve reloads or garbage guns. I have never seen an AR of any kind blow in 15+ years shootingon rifle ranges. |
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I agree under charged. If you have a malfunction (and circumstance permits) always check the barrel is not obstructed. Especially when using reloads. Spending 7 years working on a hand gun range I never expirienced a blow up that did not involve reloads or garbage guns. I have never seen an AR of any kind blow in 15+ years shootingon rifle ranges. I have never heard of an under charged round causing a kaboom in anything other than a badly overbore cartridge and when using a light charge of slow burning powder. However I'm not one to say it can't happen! I would bet the majority involve other issues already mentioned. PS and you guys think lefties are crazy to get left handed rifles! I sure don't want to look into the ejection port of one of those mini grenades! 
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I agree under charged. If you have a malfunction (and circumstance permits) always check the barrel is not obstructed. Especially when using reloads. Spending 7 years working on a hand gun range I never expirienced a blow up that did not involve reloads or garbage guns. I have never seen an AR of any kind blow in 15+ years shootingon rifle ranges. I have never heard of an under charged round causing a kaboom in anything other than a badly overbore cartridge and when using a light charge of slow burning powder. However I'm not one to say it can't happen! I would bet the majority involve other issues already mentioned. PS and you guys think lefties are crazy to get left handed rifles! I sure don't want to look into the ejection port of one of those mini grenades!
In the undercharged case with a too slow burn rate, the powder does not detonate––-it is almost impossible to detonate smokeless powder. What happens is that the powder ignites, but does not develop enough pressure to keep the bullet moving. When the free bore (the distance to the lands of the rifling) is long enough the bullet moves creating a larger volume and the pressure cannot keep-up. When the bullet hits the rifling it stops. This creates in effect a bore obstruction. Since the powder is burning the pressures rise, increasing the burn rate and the pressure rises still further before the bullet can start moving again and increasing the volume for the gases behind it. When the powder is a bit faster, the bullet does not stop since there is enough pressure to keep it moving into the rifling. This then prevents the pressure spike. Most AR blow-ups are due to too much and too fast a powder, or a bullet lodged in the bore and someone forces another cartridge behind it. The bullet in the second cartridge will often push into the case and compress the powder charge (decreasing the volume). Also there are now two bullets (twice the mass) for the powder to push against and one is much tighter in the bore. It takes a lot more pressure to get the bullets moving and since the powder burn rate increases with pressure, you get a blow-up. |
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I'm sure you've all seen the video by now. But my question is, what exactly makes an AR blow up? Is it the rifle itself? Or ammo used? Could some experts way in on this please and educate a noob. Thanks! Why didnt you text me bro.......  But what you have read above is correct. That is why you really need to watch the kinds of ammo you buy.
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I'm sure you've all seen the video by now. But my question is, what exactly makes an AR blow up? Is it the rifle itself? Or ammo used? Could some experts way in on this please and educate a noob. Thanks! Why didnt you text me bro....... But what you have read above is correct. That is why you really need to watch the kinds of ammo you buy.yepp.... i dont buy ammo that has been reloaded (from gunshows and stuff)... you never know what your really getting |
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Actually, I think it is more possibly an undercharged round. There is not much space left in a 5.56 case to extremely overcharge it, so the theory is that an undercharged round whose powder level is low enough that the primer ignites a large area of powder initiates a detonation causing a kB!. And squibs of course. I have to go with yekimak and others. Have only seen one AR come apart and from conversations with the guy afterwards (his second one to kB  !?!) I think that this is the most likely reason. Undercharge of WW748 on a HOT day, CMP match last slowfire group of rounds that had been setting in the sun for an hour.
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It is very easy to blow up an AR-15 or any rifle for that matter. Simply ignore reloading data, believe your gun is unique and is not subject to the laws of nature or physics, and load it accordingly. How many people have perpetuated the myth that reloading manuals are conservative with their loads because of liability issues. Time after time people have tested loads in the manuals with real pressure equipment and they have always reported the same - the maximums listed are indeed maximums.
I experienced a squib load this week shooting a factory IMI .45ACP 185 grain wadcutter ammo that was close to 25 years old. Primer went off just fine, the powder did not ignite. When I manual racked the slide powder spilled all over. Bullet was lodged about 1.5" in the barrel. Shoot another round behind a stuck bullet and you will blow yourself up. Almost all catastrofic failures are of this type. Someone shoots, the recoil or report seems funny, instead of stopping immediately they manually eject the round and load another. When they pull the trigger the eplosion has nowhere to go because the barrel is blocked. Violent reaction is a guarantee. WHENEVER THE RECOIL OR REPORT FROM A FIREARM SEEMS ABNORMAL - CLEAR THE WEAPON, MAKE IT SAFE AND CHECK THE BORE FOR OBSTRUCTIONS. Rarely (it does happen, but not very often) people ruin firearms by loading unknown powders, mistaken identity powders, or grossly misweighed powders of the proper type. I use weight checks to make sure I have what I think I have on the scale. It would be easy to blow up any rifle if you were to load it with pistol powders. If some how you dumped powder into the wrong container and ended up pouring 25 grains of Bullseye in a .223 case instead of 25 grains of WW-748 all bets are off. That's why a clean and organized loading bench is suggested. Only have one powder can available at any given time, the rest are stored away from the actual work area. |
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Ha, whats up Medic. Didn't want your old lady to think I was stalking you!  Nah...she was messing with you. Figured she ticked you off since you haven't texted back
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| Any ammo can be a problem or defective , but using quality ammo helps the odds. Always stop shooting and clear the mag and check out the rifle, and fired cases, when getting jams. Watch for less recoil or less bang reports. Use good quality mags that have break away bottoms to release pressure if a round blows. Never shoot holding the mag and wear quality safety glasses. Look at fired cases and primes occasional for pressure signs. When your rifle tells you it dont like the ammo you better listen , inspect, and go to different ammo. A quality AR can generally hold a blown case as it will usually rip the bolt head-extractor and exit down the blown out mag bottom, but a barrel obstruction can be worse. Never shoot reloads unless you load them yourself, and watch your factory ammo cases for problem signs and definately watch for your rifle and working correct with the ammo your using. Watch your shots on target to make sure they are there. Shooting at the same time others are shooting can distract you from a weak round that didnt make it out of your barrel. |
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Sadly, that shooter got exactly what he deserved. If you have to pound on your forward assist that many times your rifle is trying to tell you something. Learn to listen.
Inexperience can be fixed with training, but stupid lasts forever. Posted Via AR15.Com Mobile |
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You need to pay attention to each round as it fires. If it sounds different, or the recoil feels different, STOP SHOOTING IMMEDIATELY! Clear the rifle, and find out what the problem is.
There are two sorts of malfunctions that can happen here: 1. A defective primer, or perhaps if the bolt did not fully close which would prevent the firing pin from reaching the primer in the first place, the hammer will drop and you'll get a click instead of a bang. The primer either didn't detonate at all, or it gave a sort of feeble detonation - a kind of slow burn, so to speak. FIRST, wait about 15 seconds or so with the rifle pointed downrange at a safe backstop. The round may be a "hang fire", which means that for some reason the primer went off but the main powder charge didn't ignite YET - but it still could. You don't want that to happen as you open the bolt, or if you've got the rifle pointed in an unsafe direction while you're asking yourself WTF. After 15 seconds or so, if it didn't go off yet, it probably won't. You'll have to cycle the charging handle to re-cock the hammer, which will eject the defective round. You will note that the defective round still has a bullet in it. In that case, presuming the previous round fired as normal, there's no danger of a bore obstruction - but it won't hurt to look (see below). 2. If there's just enough of a detonation to pop the bullet out of the case neck, such as if the case was charged with insufficient powder, there will be no gas reaching the gas tube to operate the action. You will have to manually cycle the bolt with the charging handle. An EMPTY case will eject. BUT, do you know for sure that the bullet went downrange, or is it stuck in the bore? The ONLY way to find out is to LOOK. Remove the magazine, verify visually that there's no round in the chamber, then either peek down the bore from the muzzle, Al Gore style, or better yet, break the rifle down and remove the bolt, and look down the bore from the breech end. Safety should be the most important thing here. Presuming you're not in a fire fight with the Taliban or something, there's no real compelling need to rack that bolt and get your rifle up and running again ASAP. Even if you drop a bunch of points in a three-gun match or something, so what! Better than a blown-up magazine, at minimum, and a possible trip to the ER. I mean, all you're killing is rocks, dirt clods, tin cans, or paper targets anyway, and none of them are shooting back. Get your priorities straight, stop, think about what you're doing, and take appropriate action. If you're training up for some zombie-killing, malfunction-clearing drills can be done in your basement with dummy rounds at 0 risk. |
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I think he had an uncharged round. the primer unseated the bullet into the throat, but with the bullet not forced into the rifling, gas was able to escape past the bullet. You will note the rifle failed to cycle. He then manually ejects the case. HERES A GOOD PLACE TO STOP AND WONDER WHY, MAYBE TAKE A LOOK. He then charged the rifle with a fresh round, but the bolt fails to seat. WARNING SIGN. He then uses the foward assist to force the bolt foward. (what do you think is holding it back?) I suspect he is pounding the bullet from the previous misfire into the tube with the foward assist....He the has a failure to fire, probably because the bolt has still not seated. THIS IS A BIG CLUE. NOW WOULD BE A GOOD TIME TO PULL THE BOLT AND SEE WHATS UP. Instead, he tries a fresh round and again uses the foward assist to pound it home. And again. When he finally has pounded the previous misfired bullet far enough into the barrel to get a new round seated behind it, he gets to blow up his gun. Took a lot of effort, and ignoring a lot of signs, but he did it.
Pure speculation on my part, as I wasn't there. 
Had a sqib on a .357 revolver w/some hereya'go reloads once, just sounded and felt odd, so I lowered the hammer on the next one and popped the cylinder for a lookeesee. Gave me shivers, but was easily remedied with a wooden dowel and hammer.... I have it on good authority that Eugene Stoner was adamantly opposed to the foward assist( note it's absence from the original design and AR-10), but the Military demanded it, and we all have it BECAUSE. Wonder why he was against it?!? Course Thats just my opinion, I could be wrong! |
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Regarding the forward assist, actually the Army wanted it. The Air Force, for whom the rifle was originally developed, didn't. The Army was buying more rifles, so the Army won.
Never have thought that the forward assist was a good idea - I mean, if the round doesn't chamber, then get rid of it! I understand, however, that the Army wanted it more to able to get the bolt closed again after it was slightly opened to permit air into the chamber so as to allow water to drain out. However the original design of the AR15 bolt HAS a forward assist - it's the little scalloped-out area where the dust cover latch fits. |
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So how do you know if you have had a squib round? Is there anything you can do to notice it? New I loaded 2000 rounds for a carbine class on a single stage. I visually checked each case after dropping powder, but I got sloppy on my last 200 round batch because I was anxious and tired. Next day I shook every case from that batch to verify powder by tactile and audio sensation. Found 1 squib. Later I ended up shaking 1999 cartridges just to confirm they were GTG Posted Via AR15.Com Mobile |
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