Loads too dangerous for AR15
- Thread starter AL45
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"Ruger only" loads only apply to revolver cartridges and is a statement about how Ruger's big bore hunting revolvers like the Redhawk are built.
If you are a handloader, you can stuff a 223 shell so full of fast powder that you can blow up an AR. But ARs will handle all commercial ammo loaded to SAAMI or CIP specs.
Most catastrophic failures in ARs have to do with out-of-battery ignition or faulty bolt lugs, not ammunition.
If you are a handloader, you can stuff a 223 shell so full of fast powder that you can blow up an AR. But ARs will handle all commercial ammo loaded to SAAMI or CIP specs.
Most catastrophic failures in ARs have to do with out-of-battery ignition or faulty bolt lugs, not ammunition.
Realize that there are 2 basic cartridges, the .223 Remington and the 5.56 Nato. In most reloading manuals, you won't actually find 5.56 Nato, which is a higher pressure round. Powder charges for the 5.56 NATO may be 2 to 4 grains over the max for .223 Rem. There is also the .223 Wylde chamber which is a hybrid capable of shooting both and maintaining the slightly better accuracy of the .223 Rem chambers. 5.56 Nato should not be fired in .223 Rem chambers, but you can fire .223 Rem in 5.56 Chambers.
You really CAN'T blow up an AR, with either chamber, even with significantly over-pressure rounds using rifle powders. I put slugs in M4 barrels and fired full pop 5.56 rounds behind them, did not blow up. I over-charged 5.56 loads by 30% with compressed loads and deep seated, did not blow up. Now, if you use pistol powder, you can cause some pretty significant damage, but in most cases you will be buying new parts and underwear. If you are interested, pick up the SHOT show issue of RECOIL where I dispel some myths. Here is a photo of what happens with a 77 grain slug on a full case of fast pistol powder. The lower was polymer, and undamaged as was the barrel. The pressure was well over 200 Kpsi, and while I was not holding it, if I was, I would have gotten a bit of soot on my arms. DO NOT try this at home!
You really CAN'T blow up an AR, with either chamber, even with significantly over-pressure rounds using rifle powders. I put slugs in M4 barrels and fired full pop 5.56 rounds behind them, did not blow up. I over-charged 5.56 loads by 30% with compressed loads and deep seated, did not blow up. Now, if you use pistol powder, you can cause some pretty significant damage, but in most cases you will be buying new parts and underwear. If you are interested, pick up the SHOT show issue of RECOIL where I dispel some myths. Here is a photo of what happens with a 77 grain slug on a full case of fast pistol powder. The lower was polymer, and undamaged as was the barrel. The pressure was well over 200 Kpsi, and while I was not holding it, if I was, I would have gotten a bit of soot on my arms. DO NOT try this at home!
tahunua001
New member
some actions are stronger than others. the ruger only loads generally apply to revolvers as they tend to be stronger than smith and wesson revolvers. in 45/70 there are a wide range so sometimes they can be split between trapdoor loads, contender loads and ruger number 1 loads.
in 223 the difference in pressure and capability is so slight that there is nothing to worry about.
in 223 the difference in pressure and capability is so slight that there is nothing to worry about.
I only shoot 223 loads in AR's, but I have no doubt that given a combination of slow powders and overpressure loads, there are loads that that will cause jams or blow up an AR.
Overpressure loads will blow primers which will jam in the mechanism . This is probably one of the first things you will notice. Another issue will be ripped rims as the action will be unlocking when the residual breech pressure is too high. A lot of American lives were wasted in Vietnam due to this problem: the Government issued ammunition whose pressure curve was inappropriate for the mechanism, the rifle ripped off the cartridge rim, but did not extract the cartridge, and with 20-50% of American rifles being down in any fire fight, the VC were able to over run American positions and kill those with inoperative rifles.
In typical fashion, the military deigned there was a problem, classified everything as "Top Secret", those involved in the active coverup got promoted and lucrative jobs once they retired, and the Contractor got even more money to fix the defects in the AR15. The only losers were the whistleblowers and the dead.
You can load the cartridges so hot that the case head blows and gas goes back into the mechanism, blows the magazine out and breaks the upper or the lower.
I would be curious to learn more about your experiments, because the high pressure tests would show that the AR15 is a very rigid structure for a light rifle and well designed with features that protect the shooter in over pressure incidents.
Maybe it would be a matter of quibbling as to what constitutes a blowup, but I have many more pictures of blown AR mechanisms, but these are some of the best:
Those are some good ones Slamfire. Did you look at the photo on the one linked in my prior post?
Typically, with shorn off bolt lugs, it is due to an out of battery firing. Insufficient crimp allowing the bullet to go completely inside the case during chambering, and not leaving the bore, are the only ones I have seen like your first photo. To fracture the carrier, you have to fracture the extension and bolt if it is in battery, and the only way to get that much pressure is with pistol powder, which is the one shown in my linked photo.
Sure, they can blow up, but not with rifle powders, correct OAL and in battery.
Typically, with shorn off bolt lugs, it is due to an out of battery firing. Insufficient crimp allowing the bullet to go completely inside the case during chambering, and not leaving the bore, are the only ones I have seen like your first photo. To fracture the carrier, you have to fracture the extension and bolt if it is in battery, and the only way to get that much pressure is with pistol powder, which is the one shown in my linked photo.
Sure, they can blow up, but not with rifle powders, correct OAL and in battery.
I did look at your picture and saw the bolt fired with pistol powder.
It is possible to reverse engineer the shear strength of the bolt lugs and extension, something I have not done, but I do not believe that anyone whose design goal was a 7.5 pound rifle was going to size his locking mechanism for 200K + pounds of pressure. There has to be a limit to the load the action can carry, but I do not know the design limits. Even without knowing the loads it takes to cause a catastrophic single event failure, overpressure loads will reduce the endurance lifetime of the part. Parts are typically designed to carry a load, and carry that for a bounded range of cycles. The lifetime will be in ranges of once, 10X, 100X, 1000X, 10000X, 100000X, and infinite. Sometimes once is good enough. I am aware of a shuttle flight in which engine turbine parts flew with cracks. The fatigue experts predicted it would last one flight, not two, but at least one, and one flight it flew. The part was replaced for the next flight. (Want to be an Astronaut?) While a well designed mechanism can survive a once in a lifetime overpressure event, by luck, just based on material properties, you should not expect that part to have a normal service life after an overpressure event.
It is worth going to this thread Ruger om 44 convertible and examine the diagram:
I have never seen a post or a report of an out of battery firing of an AR15. Maybe you have, how could it happen given the firing pin is retracted until cam down?. That ought to positively prevent the firing pin from making contact with the firing pin. There is only one way I can think of, a high primer with a supported anvil. CCI has stated that a high primer is the most common cause of misfires because the anvil has to be firmly seated on something and the primer cake pushed on the anvil. Given a shallow pocket or something in the bottom of the pocket, a high primer could ignite on contact with a bolt face, but even so, given this possibility, I have never seen an out of battery event in a AR mechanism. So, have you?
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Yikes, there are a few problems with the quotes...
Metals behave differently in fatigue, and the classic examples of fully reversing loads is not applicable. Cyclic loading yes, but as long as we stay under certain specific limits with steels, there will not likely be fatigue failure in steels used for firearms. Aluminum is very different. I disagree that the fatigue life, even at proof loads, is 10k in firearms. The design point has NOTHING to due with fatigue in steel. Seems like your quoted author is only talking about materials that behave like Aluminum, but certainly not steels. Recent testing a research has also proven that the deformation limits and fatigue limit models for carbon steels are NOT applicable to Stainless steels. Go look up some S-N curves for Carbon steel, Stainless Steel and Aluminum and it should be clear that your quoted author has missed some fundamental points as it relates to fatigue and endurance limits. Steel and Titanium "classically" have distinct limits, below which the life is infinite. While, again, recent testing has shown that there is not really an "infinite" life, the testing also illustrates that the fractures initiate as machining marks, occlusions and other grain boundary issues in Carbon Steels. In Stainless Steel. actual phase change can occur if the loading is high enough.
Materials and failure analysis is what I do for a living and my Father also did quite a bit, but that is a diversion. Pressure over rated pressure will not necessarily cause a reduced service life. If crack growth is initiated or plastic deformation occurs, sure, but for modern firearms, these levels are way beyond proof.
Out of Battery, yep, several times, but it takes a mistake of the geometry sort to get there. One I suspected was an OOB firing, with sheared bolt lugs exactly like the ones you have pictures of. Put a .22LR upper on the lower for safety reasons and got firing OOB by about 1/4". BTW, on the one shown in my photo, there was no spring, buffer, or gas system, and the bolt remained in battery. If there had been a gas system, I would have seen sheared lugs most likely. But that was not the purpose of that actual test.
Apologies to the OP as we are way off in the weeds related to your actual question.
Metals behave differently in fatigue, and the classic examples of fully reversing loads is not applicable. Cyclic loading yes, but as long as we stay under certain specific limits with steels, there will not likely be fatigue failure in steels used for firearms. Aluminum is very different. I disagree that the fatigue life, even at proof loads, is 10k in firearms. The design point has NOTHING to due with fatigue in steel. Seems like your quoted author is only talking about materials that behave like Aluminum, but certainly not steels. Recent testing a research has also proven that the deformation limits and fatigue limit models for carbon steels are NOT applicable to Stainless steels. Go look up some S-N curves for Carbon steel, Stainless Steel and Aluminum and it should be clear that your quoted author has missed some fundamental points as it relates to fatigue and endurance limits. Steel and Titanium "classically" have distinct limits, below which the life is infinite. While, again, recent testing has shown that there is not really an "infinite" life, the testing also illustrates that the fractures initiate as machining marks, occlusions and other grain boundary issues in Carbon Steels. In Stainless Steel. actual phase change can occur if the loading is high enough.
Materials and failure analysis is what I do for a living and my Father also did quite a bit, but that is a diversion. Pressure over rated pressure will not necessarily cause a reduced service life. If crack growth is initiated or plastic deformation occurs, sure, but for modern firearms, these levels are way beyond proof.
Out of Battery, yep, several times, but it takes a mistake of the geometry sort to get there. One I suspected was an OOB firing, with sheared bolt lugs exactly like the ones you have pictures of. Put a .22LR upper on the lower for safety reasons and got firing OOB by about 1/4". BTW, on the one shown in my photo, there was no spring, buffer, or gas system, and the bolt remained in battery. If there had been a gas system, I would have seen sheared lugs most likely. But that was not the purpose of that actual test.
Apologies to the OP as we are way off in the weeds related to your actual question.
We are going into the weeds, I do not want to chase down the differences in fatigue life for SS, carbon steels, titanium aluminum. There are differences, and there are volumes with charts on the differences. The load carrying members of an Ar15 are an alloy steel, I don't know which, the most common alloy used in firearms is 4140, maybe you know the alloys used in the bolt lug and the barrel extension?
But, do you know the design loads for the AR15 and do you know the fatigue life? I don't.
But nothing the reference I gave was out of line with what I expect for a service rifle. As you know a service rifle has a bunch of criteria to satisfy, two that affect this discussion are weight and service life. As you probably know, because you can find these documents, the Army requirements typically specify that any rifle or pistol has to pass a 5000 or 6000 round endurance test. This does not apply to machine guns or cannons, their lifetimes are greater and their weight is greater. So, if you want to sell a light weight rifle to the Government you have to meet the weight limits (let's say 7.5 pounds) and the thing has to go bang for 6000 rounds. After 6000 rounds it is perfectly permissible to rebuild the weapon and it is OK to replace any and every part. So, while building a heavier weapon, one that goes bang forever, is wonderful, if that extra weight required for an infinite fatigue life is above 7.5 pounds, you are non compliant to bid requirements and your wonderful rifle will be excluded from any procurement decisions.
If the requirement were 6000 rounds without failure I would design the locking system to last more 6000 rounds, maybe 10,000 or 12,000 rounds, assuming everything ends up under 7.5 pounds, but I don't know the sensitivity of AR 15 system weight to increasing service life. I don't know how doubling, tripling, or infinite service life affects the weight on the rifle.
However, given how little I know, I am skeptical that the AR15 was built to last an infinite number of firing cycles, especially when the barrel wears out well before infinity, and am very skeptical that it was designed to fire an infinite number of proof loads.
It is however, a very rigid platform and one that provides good case head support. So much so, that when the Army tested a SAW in a 160 F endurance test, and stupidly, heated the ammunition to 160 F (which raised the average chamber pressures to 72 K psia). Well guess what, the SAW experienced problems. The SAW is a properly designed weapon, properly designed to function 100% with 55 K psia ammunition, but the design is not as rigid as the AR. So through dump luck the Army has not experienced (or at least acknowledged!) problems with their overpressure ammunition in the AR's, but the SAW, being more flexible, less case head support, had function issues. The SAW did not break, again testament to good engineering, but had function issues.
The Army, instead of acknowledging that they issue overpressure ammunition that causes problems in SAWS, they blamed oil!. The Army put out bulletins and warnings "don't let oil come between your case and your chamber"!
They don't dare take on FN and accuse FN of making faulty weapons because FN would show that Army Ordnance is staffed by incompetents.
Rimfires, they are dangerous with the exposed rim full of priming compound. It is entirely possible, and I have seen pictures of OOB with rim fire pistols, so I can believe an OOB in a AR15 rimfire conversion. Still I am looking for that hard proof on a centerfire version and how it could happen with ammunition with primers below the case head.
Sheared lugs sounds like the bolt was in battery. If the lugs were out of battery, what would shear the lugs off?
yes you can blow up a ar w /rifle powder
BL-C 2 ,27gn with 55 gn. bullet. looks like the posted pictures shown earlier. Made these loads 2 years ago and used it for all my rifle shooting untill I discovered CFE 223 then went to H335. Was looking for some plinking ammo so opened the sealed ammo can and blew up my ar with first round.
BL-C 2 ,27gn with 55 gn. bullet. looks like the posted pictures shown earlier. Made these loads 2 years ago and used it for all my rifle shooting untill I discovered CFE 223 then went to H335. Was looking for some plinking ammo so opened the sealed ammo can and blew up my ar with first round.
tahunua001
New member
oraysor,
those loads are a full grain above maximum posted by hodgdon which is normally a little hotter than most other publishers. you pretty much had to be compressing loads at that point and I'm willing to guess that those two years of use with that load made a LOT of stress on your gun. CFE, is a very high pressure powder, hodgdon's posted max has a PSI of 3700 over their posted max of BLC2(which you exceeded on a regular basis). H335 is also on the upper end of the pressure scale with their posted max of 53000 PSI, still 3000 PSI over posted max of BLC2.
the question was, is there any FACTORY 223 ammo which is unsafe for use in an AR15. the short, simple answer to that question is no. the not short, not simple, and in this case kind of irrelevent answer is yes, if you push a bunch of high pressure, hand loads that exceed safety standards through an AR15 for over 2 years then the gun will explode.
those loads are a full grain above maximum posted by hodgdon which is normally a little hotter than most other publishers. you pretty much had to be compressing loads at that point and I'm willing to guess that those two years of use with that load made a LOT of stress on your gun. CFE, is a very high pressure powder, hodgdon's posted max has a PSI of 3700 over their posted max of BLC2(which you exceeded on a regular basis). H335 is also on the upper end of the pressure scale with their posted max of 53000 PSI, still 3000 PSI over posted max of BLC2.
the question was, is there any FACTORY 223 ammo which is unsafe for use in an AR15. the short, simple answer to that question is no. the not short, not simple, and in this case kind of irrelevent answer is yes, if you push a bunch of high pressure, hand loads that exceed safety standards through an AR15 for over 2 years then the gun will explode.
You might be right, with available rifle powders, but you certainly can blow up an AR.
I saw an M16A1 in 1977 with not only severely fractured internals, but the left side of the upper receiver peeled away and curled like the sealing strip on a spam can!!!!
They brought me the rifle for ECOD so they could file a statement of charges against the GI who did it. The gun was toast (not economically repairable). As I recall, the lower was slightly bulged in the mag well area, although it had neither cracked or broken, it was a write off, as well.
Somehow, this was done, by a GI, in the field, in Germany, with whatever it was that he had available. The story I got told (no way to determine the truth) was that he hammered a fired blank into the muzzle, then fired a blank and the rifle came apart. I knew that there must have been something else involved, as I have seen this done, and the rifle does NOT come apart.
(fyi, a fired blank case, launched in this manner will completely penetrate the door of a deuce and a half at 30 yards. Don't ask...
)SO, you CAN blow up an AR, quite massively. But I don't think you can do it with regularly available RIFLE powder.
You can break one pretty bad with rifle powder, to the point of it being a total write off, I think, but its not easily done.