January 28, 2018, 11:59 PM | #26 | |
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"Everyone speaks gun."--Robert O'Neill I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk! Last edited by stagpanther; January 29, 2018 at 12:11 AM. |
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January 29, 2018, 12:21 AM | #27 |
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I thought having such a rifle in your part of the world was highly restricted. Sounds to me as though you may indeed have a full auto rifle. Is there a pin just above the selector lever?
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January 29, 2018, 02:22 AM | #28 |
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OK. he was just here. We completely stripped and cleaned it. It was very clean inside apart from a little carbon on the back of the bolt. Cleaned that off and inspected everything thoroughly. No damage. Nothing looked like it had been played with from factory. No marks or wear on sear surfaces nor any damage.
There is not a spring on the firing pin like ya showed me in the photos. The Rifle looked nearly pristine inside. Id be surprised if the rifle had ever had more than a couple hundred rounds through it in its life. Head space was fine. Bore is excellent. FCG looked like new. Even inspected with an eye loupe. Everything operated perfectly. I am starting to believe that it was the Federal ammo. Next step will be to head to the range and will test with different ammo and if it doesnt fault, Then will retest with the federal ammo carefully. There was nothing obvious in or on the buffer or tube. all clean with very little wear marks. no burrs. spring in good condition. Same with the buffer itself. Sorry I didn't get any photos. Only saw ya post after he'd left. Will try to remember when we go to the range. |
January 29, 2018, 03:25 AM | #29 |
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another thing no one has mentioned yet which I originally asked in my first post was about the ejecting angle. All the videos I've watched of these AR-10's being fired shows in 90 % of cases the ejected brass is exiting between 1 and 3 o clock. I read on a post somewhere that this has to do with the gas system but nowhere so far have I found anything that goes into more detail. I did notice on the day we were at the range that all of his brass was ejecting to 5 o clock instead of the 1-3 o clock angle. Does this matter or is it also an indicator of a problem?
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January 29, 2018, 06:22 AM | #30 | |
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My experience is that this can vary depending on the gas system set-up and power of ammo used--especially in the xx308 builds I've done. Even the type of powder and when it reaches peak pressure can cause variations in the whole cycling process. Adjustable gas block manufacturers will tell you that the mechanical symptoms of an over-pressured system may resemble exactly those of an under-pressured one (short-stroking, failure to eject etc.). I have verified that to be true in my experience. You mention everything looks pristine and virtually unused--but that does not necessarily mean it is fully compliant. It only takes a few thousandths of an inch variation to potentially create a dangerous condition. People assume sitting in a safe unused means that weapons remain in tune--could be--but the opposite could also be true.
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January 29, 2018, 06:29 AM | #31 |
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5 o'clock is good. Different ammo will throw brass differently. Has to do with gas flow and speed of bolt movement. Sounds like the lack of hammer spring and sensitive Federal primers caused the issue.
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January 29, 2018, 08:18 AM | #32 |
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If you're REALLY concerned about the multiple firing problem, go through the complete "new gun start up procedure". This will tell you if there's a problem with the FCG.
Oh, don't spare the lube during range sessions. If the rifle smokes like it's on fire, it's lubed adequately. |
January 29, 2018, 08:26 AM | #33 |
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Ok. That answers that. Thanks guys
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January 29, 2018, 12:01 PM | #34 |
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The first AR I assembled back in the early 90's had a similar problem. It would frequently fire 2-3 rounds. I couldn't figure out was wrong with it but happened to be at a range when a machinist familiar with AR's looked at. He determined the opening on the gas key was out of round. Replaced the part and no problems since with thousands of round fired through that AR.
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January 29, 2018, 12:32 PM | #35 |
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What does the roll mark say? Should be on the mag well
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January 30, 2018, 10:01 AM | #36 |
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OK. We went to the range this afternoon. The rifle performed flawlessly! After tentatively firing 10 mags loaded with two rounds each, He fired 6 20 round mags full of Winchester ammo without any problems. He then loaded 2 rounds of Federal ammo and it burst the two rounds. Luckily that was the last of his Federal .308 ammo so the problem won't be happening again. I then fired 40 rounds of the Winchester ammo without a fault. He now knows to keep it wet too.
Thanks to everyone for all the help. Once again you all have been a great source of information and help. Cheers |
January 30, 2018, 10:52 AM | #37 | |
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I don't know if you or your bud reload, but if reloads are to be used in this rifle, use "mil spec" primers. In the United States, the least sensitive primer is the CCI #34. The US Army developed a non corrosive large rifle primer and it was called the #34 primer. There are lots of primers, each of a different size, each of a different composition, and each of a different sensitivity. The #34 primer is a little less sensitive, on the average, than the commercial primers. That includes CCI standard, Winchester, and of course Federal. Before the US got into a trade war with Russia, Tula primers were available, were advertised as "mil spec" and they were a great primer. I am going to reference this thread in the future as it is a good object lesson. It is hard to believe but for over a half century the American shooting community were taught that "only high primers" and your worn out receiver bridge were the allowable causes of slamfires. It turns it this was a 60 plus year cover up of the design faults of the Garand type mechanism. The Garand, like the AR10, has a free floating firing pin. Unlike the AR mechanism, the free floating firing pin in the Garand mechanism is able to contact the primer before the lugs are in battery. Many shooters were injured, many Garands/M1a were blown up when their rifles slamfired out of battery. Both the Army, and their sock puppets on the American Rifleman staff, created a disinformation campaign claiming there was nothing wrong with the Garand/M14, that slamfires were all the fault of reloaders and their high primers. I can remember in the mid 1990's arguing this on the "Shooter's Forum". At the time, primer sensitivity was not a concept, the shooting community had been taught by these same sock puppets that a primer was a primer was a primer. Federal match primers were the most popular primer on the firing line, because, Federal was the only company stamping "match" on their box of primers, and of course, if you are a match shooter, you want to use match components. It turns out Federal primers are the most sensitive primer on the market by design, so reloaders were using the absolute most dangerous primers in their Garands./M1a's. And none of the in print media warned the shooting community about this. The in print media still basically ignores this, that primers do vary by sensitivity and that in semi auto's, full auto's, you should use the least sensitive primers you can find. This is glossed over because the in print media is not going to print anything prejudicial to their advertisers. They are there to educate us on what to buy, not to teach us what not to buy. If you model in print media as shills for the fire arm industry, then their behaviors become understandable as rational, predictable, and amoral. Since the 1990's, the internet community is able to discuss intelligently these issues, free of commercial profit motives, and I am pleased to read very good analyses of slamfires such as what I found here: Slamfire https://ipfs.io/ipfs/QmXoypizjW3WknF.../Slamfire.html Something that is to be understood, even with "mil spec" primers, all mechanisms with free floating firing pins can, and have, and will, slamfire because primer sensitive varies so much within a lot. Primers have to meet an average lot sensitivity, but if you ever get to see actual primer sensitivity data, you will see primers within the lot that take very little energy to ignite, be they commercial or mil spec. Therefore, when loading a military type rifle, don't point the muzzle at anything you don't want to kill. The things may slamfire. This is a tavor TAR 21, which fired well with factory federal, but slamfired upon reloading with winchester ammunition. https://www.youtube.com/watch?v=bu8Dwj7Ey8k Winchester primers vary in sensitivity, they vary by lot, so the next batch of Winchester ammunition, it may also slamfire. Commercial manufacturers are free to change their product as they want.
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If I'm not shooting, I'm reloading. Last edited by Slamfire; January 30, 2018 at 11:31 AM. |
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January 30, 2018, 11:24 AM | #38 |
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I must admit I should have twigged to the Federal thing sooner. When I was shooting Cowboy action I competed in Frontier Cartridge class which was using cartridges loaded with black powder. For other competition such as IPSC , Service pistol etc I had always used Federal primers in my ammo ( yes we both reload too) but when I started shooting Cowboy the black powder was too hot and I was blowing holes in my primers. I changed to CCI and haven't looked back.
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January 30, 2018, 11:37 AM | #39 |
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With all due respect to you and slamfire--I'm not buying the federal primer thing as your sole and only problem. Are you using commercial grade 308 win instead of actual nato 7.62 x 51 (which is what the rifle was designed to eat)? There's no doubt that the primers are different (as are the cases and the primer seating)--but the Nato ammo was never designed to function or be used interchangeably with it's 308 civie counterpart. You mentioned a faulty bolt to extension lock-up--if you are absolutely certain that is attributable to the ammo--then fine, but just getting a few mags to successfully cycle through may or may not indicate there is or is not an issue there. Just sayin'-- not trying to be snarky, just trying to say "are you sure?"
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January 30, 2018, 01:05 PM | #40 |
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"...needs to use a LOT of lube..." The thing needs a really good bath first. Dried lube isn't going to cause doubling though
A semi going FA is caused by the ammo or a worn sear/hammer. Mind you, an M-14 will double off a bench if the shooter doesn't follow through correctly. Caused by failing to hold the trigger back until the rifle finishes recoiling and pulling the trigger again under recoil. That may be the cause here too. The military issues whatever ammo the politicals buy for them. The only relation it has to being "appropriate for your rifle" is that it's the same cartridge. Original AR-10's were made to use standard NATO ball. Slam fires are caused by the ammo, not the rifle "...simply call Armalite customer service..." Neither the current commercial AR-10's(that's an AR-10 in name only) nor the current company called Armalite have anything to do with a real, select fire, 1950's vintage AR-10. And Gladstone, Queensland is in Australia. The Sudanese AR-10's(rumoured to be approximately 2500 rifles) that came through the shop, long ago, still had parts of the desert in 'em. Full of sand. Really poor maintenance by Abdul dragging 'em around the Nubian Desert. I don't recall there being any Sudanese 'government' markings. Supposedly, they had a very lightweight, fluted steel barrel fitted with a trim, prong-style flash suppressor, a bayonet lug, lightweight fiberglass furniture, and sight graduations in Arabic.
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January 30, 2018, 01:17 PM | #41 | ||
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All you have to do is search the web for slamfire incidents and it becomes obvious that these happen, that sensitive primers are the primary cause, and, it is the simplest explanation for these events:
SLAMFIRE IN SKS 7 Dec 2010 Quote:
AK47 Saiga Slamfire Quote:
20 Feb 2008 Shotgun News, Article “ Micro Galil, The Ultimate Krinkov” Author Peter Kokalis Page 12 “Most Kalashnikovs have inertia firing pins, without an associated spring. The initial lot of Galils brought into this country by Magnum Research INC. also had no firing pin springs. The Micro Galils that I examined in El Salvador were not equipped with spring-loaded firing pins either. Military small arms ammunition primers usually have relatively hard cups, which are not easily touched off. American commercial cal .223 Rem ammunition, including Winchester ammunition often features fairly soft primer cups. In 1983, Winchester ammunition in particular caused several slam-fires and all Galils offered for sale in the United States were quickly retrofitted with strong firing pin strings. “ 29 August 2007 CENTURY INTERNATIONAL ARMS, INC. 236 Bryce Boulevard Fairfax, Vermont, U.S.A. 05454 Tel: (802) 527-1252 Fax: (802) 527-5631 Date: August 29, 2007 Subject: Galil and/or Golani Semi-Auto Sporter Rifle We are requesting that customers who purchased the Galil and/or Golani Semi-Auto Sporter that have serial numbers between GAL00001 and GAL02393 send in their firearm to us as we have modified the bolt and are installing a new firing pin and firing pin spring to ensure that your Golani offers you the utmost safety and reliability. All Galil and/or Golani rifles that have the letter "F" or "X" on the bottom of the receiver front cut off have already been upgraded and your rifle does not need to be sent in to us.If you are a dealer, please provide us with the names, addresses and contact information of the purchasers of these Galil/Golani rifles. We will contact them directly. If you are contacted by these customers, please have them call us at 1-800-270-2767 to obtain a return authorization. We appreciate your cooperation in this matter and hope to have this situation resolved as quickly as possible
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January 30, 2018, 01:51 PM | #42 |
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Slamfires happen sure because of ammo/primers--not saying they don't. My take on the initial description is that there is potentially more than just that going on. What is the protrusion of the pin past the bolt face? Is it sharp/round? Could it be hanging up inside the bolt allowing it to "overimpact" the primer,? is there proper bolt to extension lock-up and headspacing? these are just a few of the things I'd want to know with some degree of certainty.
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January 30, 2018, 05:26 PM | #43 |
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The end of the firing pin is round not sharp. The bolt is locking up fine and head space is spot on. The rifle was very clean when purchased and there are hardly any wear marks inside on any of the moving parts.
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January 30, 2018, 06:09 PM | #44 | |
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"Everyone speaks gun."--Robert O'Neill I am NOT an expert--I do not have any formal experience or certification in firearms use or testing; use any information I post at your own risk! |
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January 31, 2018, 04:19 AM | #45 |
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It is all good. working correctly and in excellent condition. Im fully aware if it is equipped to be semi auto only or select fire/auto capable
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ar10 , buffer jam , burstfire , malfunction |
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