Unfortunately though sometimes the best researched plans do not uncover shortcomings of the AR and in this case the 9MM AR. If there is no problem in the non-problem rifle and the problem rifle continues to have the binding issue, this leaves the problem rifle's upper as the problem. Get rid of fancy BCG sand use a standard one. Concrete and rebar 12in thick ceiling, walls and floor. I removed the casing and re-assembled. The AR-15 bolt carrier group, or BCG, is a critical and often misunderstood piece of the AR-15/M16 upper receiver. The Sig Sauer P320: the multi caliber,. I did not see any problem with the lower. It will chamber a round alright, but takes a great amount of force to pull it back manually. The bolt carrier group is the heart of any AR10/AR15/M4/M16 type rifle, carbine or AR pistol. $154.99 On sale: $144.14 In Stock. http://www.bushmaster.com/anatomy_bushmaster.asp. Also have you tried to lightly let the charging handle go forward just to see how easy it is for a round to go into battery? Laziness is not an excuse. AR-15 Nitride Bolt Carrier Group Mil-Spec. Re: help!!!! That's really dirty. Did you run polymer coated ammo by any chance? I did it last weekend. Pull the Bolt back to extend it and turn the Cam Pin 90 degrees. . See if there's any damage to the 45 degree relief cuts. I know, dumb as he.. and not paying attention. I always disassemble new BCG's, clean and over oil, then sit in front of the tv for an hour or so and manually rotate, push and pull on the bolt in the carrier over and over until the movement is smooth and without any rough spots. M16 Diamond (DLC) Bolt Carrier Group Out of stock SALE. Do this a couple times and it should free your BCG up. And when this happened to me it ruined my day of shooting and did know how to fix the issue until later when I got back from shooting and looked up solutions on the internet and it took me many searches to find this method so I figured I would pay it forward and upload a video of my own to help other ar15 owners in case they need to ever perform this technique and get their rifle back to working order. , the company's American branch. We offer bolt carrier groups for various AR-15 builds. Also the charging handle lever, rails, and CH race in the upper. i have a few thousand rounds on mine and no issues or deformation. TLDR: Your rifles are fine. If you didn't spray it down with brake cleaner or something prior to snapping the photo, that thing is beyond dry looking to me. Does the BCG move freely into the upper without the lower? Immediate Action: " Tap, Rack, and Reassess ". I took out the XPB BCG and put my original BCG back in and it runs smooth after that. bolt carrier group could lack enough force (generated by the expansion of the action spring) to feed, chamber, or lock the bolt . Try this-put it back together. Toggle menu. The bolt carrier is sticking out of the back of the upper receiver about 1/4". Take the advice from everybody that posted. It is stuck! Don't forget, you can always check for a live round in the chamber by inserting something down the barrel and seeing where it stops. Batch MPI and HPT tested. My account; Checkout; GEAR UP! 7.62 x 39mm Caliber Bolt Assembly Nitride $ 99.95 $ 69.95 SALE. If you have another BCG I'd try it. !echo: don't have to mess around with buffer springs and trigger springs, a drop in unit, has a trigger lock where you can't out run the bolt. Had the gun been cleaned before it was put up? The carrier then moves forward creating a double feed and jamming said casing into the outside edge of the feed ramp (I think?). This unfortunately allows the 9MM bolt to travel further down the buffer tube than necessary. High-quality AR15 Bolt Carrier Group (BCG) at Affordable Prices. Yup, do the nosedive, either that or get a hacksaw.sounds like you might have gotten a pebble or something in there or possibly a dent in the buffer tubeor, maybe the little detent that keeps the buffer spring and buffer in the tube popped up somehow. Ok, I am a total noobie. 227-GTBCG | Guntec. "After attempting this a few times I called another guy at the range over and we pulled from two ends of the gun, me from the barrel and him from the charging handle.". From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm. When the bullet passes by the gas port , the bur shaves a little off the bullet and the gasses send it down the gas tube back into the BCG . My experience is that when a bolt locks up, with nothing in the chamber, it's always been a popped primer/anvil in there, and they often fly out when you jack it open. Choose wisely with AT3 Tactical. I was at the range today and had a FTE. Solution Part Three I have learned over the years that all AR-15 recoil springs are not created equal. Right to Bear Arms and Supply proudly sells these core components from top-of-the-line brand names, including Anderson Manufacturing, Rock River Arms, Spike's Tactical and WMD Guns. The 9MM AR platform requires some specialized rifle parts to function reliably and prolong longevity of the hardware. Recently bought a house and it had a bomb shelter in it. Yes, maybe not the best way to treat your rifle during peace time, but still a handy method to practice and know in a pinch. don't worry, you can't break it. ATTN: Here is the link to a new higher quality and more informative video I made showing this technique and explaining what I think causes it, and how to keep the issue from happening again.https://youtu.be/S_wLVeBOJgII show how to use the mortar technique and simulate how my AR-15 bcg locked up with a round chambered and a bolt carrier group that wouldn't budge. Specs: Mil-spec Carpenter No. Caliber / Gauge: .308 / 6.5 Creedmoor / .243 Winchester / .22-250. B2-K630-A001-0P. made via mim so some longevity issues may arise sometime in the future. Re: Stuck bolt carrier group Post by Roadrunner Sat Feb 14, 2015 2:58 am Might be possible to take a wood dowl and drive the bolt back into battery from ejection port. They also drilled the gas port out a little larger since I am using a low mass carrier and adjustable gas block. Those vids are insane. Well I would completely take that BCG apart and wash and clean it up good, then lube real well, it looks dirty to me, I don't clean my guns every time I shoot them and none of my BCG's look that dirty, also being a Sharps BCG, I would pick up a back up BCG. If you do that, remve the end plate slowly so the spring and detent for the take down pin doesn't come flying out. Thanks so much for your helpful reply. (I had my M&P15 do this occasionally when using steel case ammo I never could figure out what it was about the steel cased ammo that was causing the problem) Have you tried to manually run some rounds thru it with a full magizine to see if any get stuck? You're currently reading page 1; Page 2; Page 3 . I would start by replacing that bolt/carrier. . Then point the muzzle straight up and rap the butt sharply on the ground. Lo and behold, I loaded my first mag with three rounds to zero the gun in and, "click." Failure to fire. About Women's Health Newsletter Customer Care Advertise Media Kit Other Hearst Subscriptions Subscribe Give a Gift. The bolt seats very early in the cycle. BCA AR-15 Bolt Carrier Group Black Nitride. You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers. 158; HP/MPI Inspected bolt I would just take off the castle nut and unscrew the buffer if nothing else. October 22, 2019 2:57 am Reply Gary. Perhaps it's the zoomed pic but that bcg looks like crap. Car parking multiplayer gearbox tips. Is it difficult to push the rear takedown pin in? ORION TRAINING GROUP; You can also check: Best Budget AR 10 Barrels. I do, however, keep the barrel extension and chamber relatively clean. Ejects the spent cartridge after firing. $157.49. When you install it, youll slide it into place through the rear of the receiver until it locks into place. This should be enough thrust of inertia to get the bolt carrier assembly to come forward. Do this a couple times and it should free your BCG up. The image below gives a nice breakdown of the parts in a typical BCG. Do I need to remove the buttstock? stock trigger has a heavy pull and even heavier . ? Check it out at this link:https://kydexowbholsters.com/firearms-legal-protection-costFirearms Legal Protection provides uncapped legal defense for members who use a firearm (or any legal weapon) in self-defense or the defense of others.If you found this video helpful and you would like to support the channel, please buy me a coffee! 276-BCG15 | Bear Creek Arsenal. The bcg should come right back. $162.54. Clean the barrel nut lugs. The BCG is all the way back. But be careful with that muzzle. Wanted to share my fallout vault door. Probably 2004 or older. Press J to jump to the feed. I can take out the pins and the upper an lower come apart a bit, but I can't completely remove them. I have never seen a carrier look like yours. [ARCHIVED THREAD] - Bolt carrier stuck in buffer tube. Just get one of the Brownells 308AR Bolt Carrier Groups, if you're stuck. The bolt carrier and Bolt would not fully seat. Press question mark to learn the rest of the keyboard shortcuts. It's nice to know whether or not it's live, even though it is going to be treated like it is anyways. What BCG? AR-308 Accuracy problems. Add to Wish List Add to Compare. Me being relatively new to the AK, but not new to disassembly/reassembly of mechanical things, I can tell you don't force anything. Or, You might have a burst shell casing that's hung up on the Bolt. 20 BA 6ARC barrel, 16 SLR Handguard (mlok), Odin Works 6ARC BCG, TriggerTech AR-15 Trigger. Shop KAK AR-15 Lower Parts Kit | 10% Off 4. LANTAC E-BCG Nickel Boron Enhanced Bolt Carrier Group EBCG (2) Sale. Jones. Obviously, if the fit is too tight for the "problem" BCG to work in the "problem" rifle, it might get stuck in the buffer tube. There might still be a problem with the problem rifle's lower receiver extension (a.k.a. It seems there is a ridge in the inner channel and if the bolt is pushed too deep into the carrier, the gas rings stick on that channel. Try the Mortar thunk first, I forgot about that. Rating: 97% Regular Price $139.99 Special Price $99.99 $79. Sometimes if the cotter pin is put in wrong it can catch. 1,592. . According to my brother, our Vietnam veteran, "mortaring" was unofficially adopted during fire fights when someone was shooting at you and your life was on the line. 1. I never thought it was going to open! Add to Cart. ARFCOM is full of answers, mine is just one consideration. Strangely enough, the problem BCG works perfectly in my personal AR. S197 Gunny Sergeant Full Member Minuteman . Was in a hurry putting my MPX back together after cleaning and put the bolt carrier group into the upper receiver backwards. Some thrifty and clever shooters have added spacers, five stacked quarters etc in their buttstock, added weights to their buffers and made modifications to the buffer to increase its overall length and weight. How did you install the barrel? JavaScript is disabled. Installed the safe door with 4 guys lifting it up as it weighs 500 pounds. Search. Step One: Complete AR15 Disassembly - Bolt Carrier Group. Keep reading below. mortaring your rifle fixes this type 4 malfunction that occurs in the AR15 weapon platform. Only problem is now the bolt carrier is stuck back all the way and won't go forward. Than, lift the rifle up about 1 foot or so and bring it onto the ground with considerable force. Pull the bolt back and rotate the cam pin 90-degrees. Or stuck on an empty chamber? Feedback Score. Use a quality recoil spring. Did I totally screw it up? Its an Anderson Lower, Pre-assembled anderson upper, rear take down goes in like normal, and the BCG does go freely into the upper. Perhaps a tad catawampus or debris. 9MM AR Broken Bolt Stop | 9MM AR Broken Bolt Catch. Service consists of a few blasts of Brake cleaner, a few pulls through with a boresnake, and a drop of lube everywhere the BCG gets shiny. View Details Aero Precision AR-15 PRO Series Bolt Carrier Group (BCG) - Black Nitride . You might want to pick up a cheap DS arms BCG just to have on hand. Thanks for the replies. Running it suppressed most of the time with minimal lube it still runs well. This is odd. You might not have noticed. Allowing the firing pin to strike the primer on the chambered round. You dont need any tools to break down the bolt carrier group for detailed cleaning.Website Article: https://kydexowbholsters.com/how-to-disassemble-clean-an-ar-15-rifleFor detailed Ejector and Extractor Disassembly, go to: https://kydexowbholsters.com/how-to-disassemble-an-ar-15-bcg-bolt-carrier-groupLinks in this description are affiliate links to help support the channel. Short and to-the-point Video: AR-15 Bolt Carrier Group Disassembly (BCG) and Reassembly is really easy when you know what to do. You could also look at the forward assist. I have had military rifles where the part of the forward assist that actually contacts the bolt breaks and locks the bolt forward. #mortartechnique #ar15charginghandlestuck #stuckcharginghandle0:00 Thumbnail Intro0:06 My 1st hand experience with this type of malfunction0:45 re-creating the malfunction with an empty shell casing1:32 How to fix your ar-15 malfunction using the mortaring technique2:08 problem solved! most likely the cheap amazon prime sights thats killing your gun. Next. The BCG moves freely already. Create an account to follow your favorite communities and start taking part in conversations. If the upper had been used/fired before and they used steel cased ammo . I bashed the forward assist, but bolt is seized hard. Resetting the hammer in the lower receiver. I read the title (What can cause a bolt to get stuck?) Only $ 149.99. Did you see the FBMG Saiga 308 threads or the AGP threads holy lord. Reactions: ken4570tc in WY. Assuming that your upper is still attached to your lower start by making sure your bolt is in battery and then push the rear pin (called the takedown pin) till it clicks and is held captive on the right side of the receiver. When you put the upper from the problem upper on the non-problem lower, does the BCG from the problem rifle bind in the buffer of the non-problem rifle? but i thought i would post this as a detailed guide. Took it back to the range today and ran about 15 rounds through it and it misfired. In a quick powerful motion shove the rifle forward and hang on causing it to come to a sudden stop. It's a solid bolt carrier group, with a few upgrades over a true mil-spec bolt carrier group. CONFIRM CANCEL. Foreign debris, some random smashed small roll pin (not an AR part) fell out the muzzle after trying the nose-slam suggested in comments. I was using Federal .223 FMJ rounds. It is comprised of the bolt, carrier, extractor, ejector, gas key, gas rings, cam pin, firing [in, and the firing pin retaining pin. Solution Part Two Some shooters have reduced recoil and improved reliability buy using a 9mm AR buffer that in addition to being longer than standard 9mm AR buffer it is also heavier. The Lower Parts Kit for AM-15 includes the following: Bolt Catch . Was the bolt stuck with a round in the chamber? AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types. I'd have a close look at the chamber face. It is not stuck in battery. Add to Wish List Add to Compare. The bolt carrier group is complete; before continuing lightly apply your oil/lube across the entire BCG but especially the contact . Add to Wish List Add to Compare. Centurion Arms Bolt Carrier Group Centurion Arms C4 Bolt Carrier Group was created with HP/MPI tested bolts and marked to give you the ultimate confidence in your weapon system. It may not display this or other websites correctly. $289.95. Packaged 7.62x39 Bolt Carrier Group Assembly B2-K630-DA00-0P Bolt Carrier Group Assy., 5.56 NATO, M16 Profile, Nitride Bolt & Carrier, RF85 Treated When I manually pull the carrier all the way back (past the trigger "friction"), it sounds a . Been playing this a lot with my teenage son, and having a blast. When I let the BCG go forward, won't go into battery enough for the BCG to clear the buffer tube. Took a few whacks. If the problem still occurs in the problem rifle, then those two components are not contributing to the problem and the issue is the alignment of the upper to the lower receiver extension. You may have to lightly push on the FA, but you shouldn't have to jam on it to get into go into battery. SALE PRICE: $137.75. 99 Save up to 20% when you buy more Buy It Now Top Rated Plus. You want reliable function, be reliable and clean it after you shoot it and keep it in top working condition. My personal preference is the Hahn and Heavy Buffers offerings. 16" 5.56 / .223 1x7 GOVERNMENT 4150 CrMoV MELONITE NITRIDE BARREL - MID-LENGTH GAS. Look for the shiny spots in the upper caused by the bolt carrier. I was able to separate the upper from the lower. Or am I stuck with replacing the entire BCG to get an M16 bolt carrier? AT3 AR-15 Bolt Carrier Group - 5.56 NATO/.300 Blackout - Nickel Boron. Can't say I'm in favor of "mortaring" the rifle. Got it. If that is indeed the case and he only fired a few rounds to test , carbon build up in the chamber was never the problem . In stock QUICK ADD . Shop CMC Triggers Enhanced AR Bolt Carrier Group | Up to 10% Off 4.3 Star Rating on 6 Reviews for CMC Triggers Enhanced AR Bolt Carrier Group Best Rated + Free Shipping over $49. You are using an out of date browser. If it's nw some of the treatments of metal can be a bit less than desirable which is normally remedied with running a little wet (not dripping but WET) and running a few magazines through it. Then push the rear take down pin and open the action as normal. The apparent problem is that the "problem" BCG is wider than standard and your "problem" rifle's upper (and probably lower receiver extension) is slightly smaller than average. Its always nice to exclude thing as being the problem . Those pictures don't help. This full auto carrier is heat treated and precision machined. here is the album of photos, let me know if there are any others i should include: http://imgur.com/gallery/ezQxC. WMD Guns AR15 Bolt Carrier Group - NiB-X (Faceted) $164.00. Is this a complete lower (hammer, trigger installed)? Now the bolt/carrier is sticking like crazy. Can you see the bolt carrier through the mag well? If you have any experience to offer send us a message. Let me ask you a question. AR15 5.56 / .223 Nitrided BCG Complete Bolt Carrier Group. (Ok, i admit, it was a CMMG bargain bin). The bolt should be centered properly. If the bolt carrier from the problem rifle binds in the non-problem rifle, the bolt carrier from the problem rifle might actually be the problem. No wonder it is locking up. Insert the Cam Pin through the Bolt Carrier opening and into the Bolt so that the flat bar on top of the Cam Pin is inline with the Bolt Carrier. Well, I am sitting in front of the tv anyway doing nothing. If the BCG is that far back it shouldn't be too hung up. The quickest way to find problems with a weapon is to simply shoot it and shoot it a lot. Out of stock. Was able to unstick the bolt carrier and the other good news is no round in the chamber. Courtesy Firearms History. Faxon 5.56/300 BLK Gunner Light Weight Bolt Carrier Group Nitride M16 Bolt Carrier Group AR15 BCG. Shop Faxon Firearms 5.56/300BLK M16 Bolt Carrier Group | 17% Off Customer Rated on 11 Reviews for Faxon Firearms 5.56/300BLK M16 Bolt Carrier Group On Sale + Free Shipping over $49. 26 items . When the thickness of five stacked quarters .345 is added to the length of the Colt 9mm buffer we conclude our 9mm buffer needs to be approximately 3.645 long! Here is a video on how to do it. (with a live round in the chamberLOL. I hadn't done much of anything since the previous day except to slide the bcg in and out of the chamber about twenty or thirty times really quickly to make sure they were moving and functioning fine. I put it in the safe. The bolt carrier group controls all functions of the AR15 - chambering, firing, and extracting spent rounds. Charpy C-Notch. $124.95 On sale: $114.95 Back Order. So I tried to lube it up but its still very rough and feels like there is a lot of friction going on. Keeping the gun pointed in a safe direction-preferably muzzle up, hold the gun by the handguard and the charging handle. Usually they are older rifles and have probably seen more abuse than yours. Well, when I had it apart earlier the buffer spring was staying in the buffer tube. Last edited by Redbeardsong; 01-14-14 at 22:53 . I put another fifty rounds or so through the gun. Snipers Hide is a community of Snipers of all kinds, focusing on long range shooting, accuracy, and ballistics. Maybe there is/was a bur in the barrel at the gas port . Return the BCGs to their original rifle and swap the charging handles. Taking the lower off didn't change a thing, so the problem is definitely limited to the upper. 499. Sounds like your buffer tube may not be threaded in far enough to keep the retainer pin from popping up, causing it to catch the bolt carrier when it goes past it. Founded by Frank Galli in 2000, Snipers Hide has been offering informational videos, podcasts, and other support to its users in one location. Take off the stock, loosen the castle nut, and unscrew the buffer tube. I had a broken decapping pin from a reloading die end up in my chamber once. Sale. If done correctly it will not damage the rifle and is a much safer way to get a stubborn round out. Safety Guideline's for using this technique3:30 Outro LANTAC 223/5.56 E-BCG Full Auto Style Bolt Carrier Group - Nickel Boron. Shop for Rifle Bolts & Bolt Carrier Groups at Brownells! AR15 5.56 Bolt Assembly Nickel Boron $ 109.95 $ 74.95 SALE. $129.99. You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers. 800-741-0015 . Copyright 1996-2023 AR15.COM LLC. I read earlier in posts about cleaning and will say this in my experience as long as you have your stick lubed up with a decent CLP, it really shouldn't matter how dirty it is given your AO. You must log in or register to reply here. My AR's are wet inside. The Whisper was first based on the little .221 Fireball cartridge cas. Anyway shot it Monday ran 60 rounds through it no problem. "Tap" your magazine to be sure it is properly seated. I dabbed a tiny bit of clp around the bolt, inside the carrier, where the rings are. Could be a combination of tight tolerances and baked on carbon. Basically your gun stopped shooting, something doesnt fit or worst of all your gun experienced a hardware failure. You are correct sir! It might not be square. Should I try freeing it up myself, or take it to an armorer? Put your pins back in and smack the buttstock on the ground. Because it's a nickel boron bcg, I was hoping this would be the magic solution that prevented me from having to lube anything. K. ken4570tc in WY Gunny Sergeant. The charging handle moves back and forth easily now. Clean the friggin' thing and lube it. I've had the same situation happen to me once before and it turned out that the round had a slight bulge around it's base. Get an AR-10 bolt carrier group and get to shooting. Insert the firing retainer pin (aka cotter pin). That would meen that chamber has never seen a steel case . Don't think so. This wouldn't be the first time I'm wrong but if possible try running your stick with a standard mil-spec/phosphate finish BCG and see what happens bro. IMHO simplest answer is your BCG is that nickel boron type and could possible be on the thick/over finished side and if that's coupled with a bolt that's a hair on the overcut sized=lock up in my opinion. Its an American Tactical upper and an 80% built lower. LANTAC 5.56/.223 M-SPEC Bolt Carrier Group - QPQ Black Nitride. It cleared fine. I pretty much run a magazine, wet th bcg, wet, etc for a couple hundred rounds. Put a heavy lube application on the 4 rails, on the gas rings, on the cam pin, the forward and rear facing lugs of the bolt, a smidgen on the firing pin, and one drop of oil worked into the ejector. So there's a direct relationship between the buffer and the bolt. White Label Armory 5.56 Bolt Carrier Group Billet Extractor Blue PVD M16 AR15 BCG . The AR-15 bolt carrier group contains vital components for proper functioning of your firearm. Going back to the question of whether or not the upper from the problem rifle works fine with the non-problem lower, if it does, then the issue might be tolerance stacking. Hey All, New to the AK world so please excuse the lack of knowledge. Suggestions? I do not run "wet" and rarely clean with less than 500 rounds fired since the last clean/lube. Expand. If you have a standard stock, you can remove the upper buttplate screw and insert a small rod and tap the carrier forward. So I was shooting my AR last week, and it was functioning fine. Maybe try a good hard hank on the Charging handle. The BCG moves freely already. Is/was the upper new ? Which in turn fires the bullet. Free open world with real gas stations and car services. Have you pushed the front take-down pin out also? Also, there are springs and pins that work with the . Does the round at all look deformed? With all this great advice, let us know how it goes. A $34.95 value! I have also traded out the charging handles on both rifles and have tried all combinations of BCG's and Charging handles on both rifles with no differences made, so the charging handle seems to be alright. There is a couple reasons for this common issue of a broken bolt stop, broken bolt catch with the 9MM AR platform. AR-9 9MM BOLT CARRIER GROUP - GLOCK AND COLT BCG - WMD NiB-X NICKEL BORON. I also oil liberally for the first 500 or so rounds. 4 (100%) "Mortar" it. I'm not sure. Issue is that bolt won't rotate/slide back inside bolt carrier. SALE PRICE: $89.99. A call to armalite confirmed this. The magazine is out. This video will show you how to disassemble your Sig Sauer P320. Short and to-the-point Video: AR-15 Bolt Carrier Group Disassembly (BCG) and Reassembly is really easy when you know what to do. Toll-Free: +1-800-504-5897 Live Chat Help Center Check Order Status. What you are going to have to do is "mortar" it. I did the mortar maneuver. You got to lube these rifles . Clean each well and lube well. I traded out the BCG on the problem gun with my good BCG and it works just fine. This energy and velocity combined with the over travel condition of the bolt cause premature failure of the 9MM AR Bolt Catch. "Rack" pull the charging handle of your AR-15 back swiftly with ample force and release it . I would never let any of my ARs look like that. . Angstadt Arms Bolt Carrier Group - 9mm. Re your edit - ha! Up to this point in time, I've not had any problems achieving this with common milspec BCG parts. When i work the bolt via the charging handle, the bolt will get stuck in the buffer tube. The case wound up being stuck in the chamber (it didn't burst or anything, but was stuck in there pretty good). TFB Review: Sharps Xtreme Performance Bolt Carrier Group. !2:14 My theories and speculation as to what causes this malfunction to happen2:51 Asking for viewers opinions on what causes this common malfunction3:20 IMPORTANT!! usmc to&e website; who makes solgw barrels. That stupid bolt may be getting jammed into the chamber and locking it up.