survivalshop Posted August 26, 2014 Report Share Posted August 26, 2014 What if your pleasantly surprised that barrel is a good shooter ? You may not know that for a few hundred rounds , or more . Action should be dry for head spacing , at least wiped down . Do all the break in & safety tests for safety sake . I would use a dab of Mil Spec or its equivalent grease on the back edge of the bolt lugs , less is better . Let us know how she roll's . Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 27, 2014 Report Share Posted August 27, 2014 He knows that already, ss. I'm just sayin'... Quote Link to comment Share on other sites More sharing options...
Owl21 Posted August 27, 2014 Author Report Share Posted August 27, 2014 (edited) Headspace checks out. It will cleanly chamber the GO gauge. NOGO will not chamber. 1. After the first round of polishing, the chamber is only a little better - One mortar attempt to eject instead of 3 - 5 attempts. 2. After the second round of polishing, the chamber is still tight, requiring the round to be mortared to be ejected. I am using a 308-AR Chamber Maid chamber brush, Flitz, and jeweler's polish. 3. I changed to a new Chamber brush and polished for a third time to no avail. In total, a brush was spinning inside the chamber for 25-30 minutes with all three polishings combined. The chamber needs more than polishing. 4. I chambered several other types of 308 ammo, and the FGMM 175 SMK factory ammo could be ejected without mortaring, but still took considerable effort on the charging handle to free the round. Maybe it will wear in with some firing? I don't know. Picture after second polish Edited August 27, 2014 by Owl21 Quote Link to comment Share on other sites More sharing options...
survivalshop Posted August 28, 2014 Report Share Posted August 28, 2014 Looks clean . Quote Link to comment Share on other sites More sharing options...
StainTrain Posted August 28, 2014 Report Share Posted August 28, 2014 (edited) Headspace checks out. It will cleanly chamber the GO gauge. NOGO will not chamber. 1. After the first round of polishing, the chamber is only a little better - One mortar attempt to eject instead of 3 - 5 attempts. 2. After the second round of polishing, the chamber is still tight, requiring the round to be mortared to be ejected. I am using a 308-AR Chamber Maid chamber brush, Flitz, and jeweler's polish. 3. I changed to a new Chamber brush and polished for a third time to no avail. In total, a brush was spinning inside the chamber for 25-30 minutes with all three polishings combined. The chamber needs more than polishing. 4. I chambered several other types of 308 ammo, and the FGMM 175 SMK factory ammo could be ejected without mortaring, but still took considerable effort on the charging handle to free the round. Maybe it will wear in with some firing? I don't know. Picture after second polish Just call the vendor you bought it from and tell them what is happening. See what they will work out with you. Edited August 28, 2014 by StainTrain Quote Link to comment Share on other sites More sharing options...
Toolndie7 Posted August 28, 2014 Report Share Posted August 28, 2014 whats the back of your bolt lugs look like? Smooth ? or coated with crap? Also is the bolt face clean and smooth where it contacts the case? Quote Link to comment Share on other sites More sharing options...
Owl21 Posted August 28, 2014 Author Report Share Posted August 28, 2014 whats the back of your bolt lugs look like? Smooth ? or coated with crap? Also is the bolt face clean and smooth where it contacts the case? Everything is new, never fired. The Nickel Boron bolt and carrier are pristine and polished, including the bolt face. I have been cycling the FGMM 175's through it. I now have about 200 cycles and either it is getting a little easier to cycle, I am getting accustomed to it, or I am building extra muscle. I am going to try to put some rounds down the barrel next week. Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted August 28, 2014 Report Share Posted August 28, 2014 Face palm! You haven't shot this? It should break in fine with round count and lots o lube Quote Link to comment Share on other sites More sharing options...
Toolndie7 Posted August 28, 2014 Report Share Posted August 28, 2014 :laughing4: lol. Yeah shooting this will open it up a little. Quote Link to comment Share on other sites More sharing options...
Owl21 Posted August 28, 2014 Author Report Share Posted August 28, 2014 Face palm! You haven't shot this? It should break in fine with round count and lots o lube Out of over 100 new AR rifles I have either handled, personally built, and/or owned, I have never had to mortar the rifle to get an unspent round to eject. Had I bought a new rifle and in the process of initial safety checks found that I had to mortar rounds, said gun would promptly be returned. I do not think that any manufacturer would knowingly allow a firearm in such a condition to leave the production line. Even if they would, I would not, especially when my name is on it. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 28, 2014 Report Share Posted August 28, 2014 Out of over 100 new AR rifles I have... How may of those were .308 ARs? Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted August 28, 2014 Report Share Posted August 28, 2014 How may of those were .308 ARs? This! Quote Link to comment Share on other sites More sharing options...
Owl21 Posted August 28, 2014 Author Report Share Posted August 28, 2014 How may of those were .308 ARs? Less than 10, one that I owned (but never fired.) They all cycled fine. Is there a concensus that it is normal for new .308 AR's to have chambers so tight that mortaring is required to remove an unspent factory cartridge from the chamber? If so, I will stop messing with it and just shoot the piss out of it for a while. Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted August 28, 2014 Report Share Posted August 28, 2014 Many have been, that's why we tell people"run heavy lube because these rifles are tighter with tolerances than the smaller platform and parts need to mate" Quote Link to comment Share on other sites More sharing options...
Owl21 Posted August 28, 2014 Author Report Share Posted August 28, 2014 (edited) Many have been, that's why we tell people"run heavy lube because these rifles are tighter with tolerances than the smaller platform and parts need to mate" Ok then. Run it wet it shall be. (and here I was thinking SAAMI specs meant something in the fit of factory ammo and chambers...silly me) Edited August 28, 2014 by Owl21 Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 28, 2014 Report Share Posted August 28, 2014 SAAMI is for Maximum Cartridge and Minimum Chamber. Tolerance stacking comes into play, as well as condition of the tools in cutting chambers. That's what you're running into. 308 Winchester SAAMI.pdf Quote Link to comment Share on other sites More sharing options...
Owl21 Posted August 28, 2014 Author Report Share Posted August 28, 2014 Thanks 98, and everyone else who has contributed. At this point, it passes all of the safety checks, and it is polished to a higher sheen than a chrome bumper on a '69 Chevelle SS at Barrett Jackson's. So I am going to put a new gas block on when it arrives early next week and then go break it in and see how it runs. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted August 28, 2014 Report Share Posted August 28, 2014 Honestly, if it was mine, I'd just lube the hell out of it (don't forget to lube the buffer and inside the receiver extension - that doesn't need heavy lube). Then I'd take it out and shoot the piss out of it with factory off-the-shelf ammo, be it cheap or match, doesn't matter. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted August 29, 2014 Report Share Posted August 29, 2014 (edited) The question is not how many rifles you were lucky to build with miss matched components & they worked fine , the question is how many did you build with this brand or manufacturers NIB coated BCG & in 308 ? Do you believe the rifle manufacturers don't have rejects that have to go to there custom shop to find why they malfunction or fail there test fire test ? You will never know how many fail & have to be reworked in some minor way . I can never understand why some people build these rifles & wonder why they don't work right away , using parts from a half doz. manufacturers . Its why Gunsmiths build & repair firearms & you are jumping into a field that many really don't have the experience & expertise to handle .Because some one builds a few rifles & doesn't have a problem & then through the laws of probability , they get one that because of tolerance stacking or other things , doesn't just spring to life . Its where experience come into play & why Gunsmiths get business , firearms do have malfunctions from various reasons , one being dirty components & plain out worn out parts . When you jump into the build your own , just like reloading , its a learning curve , although real Gunsmithing is by far the most complicated , just think of how many different firearms one has to know to be a competent Gunsmith, its really mind boggling . So , you had a new platform rifle & you think something is wrong with it , it was going to happen sooner or later if you build enough . Test fire the rifle , playing with cycling live rounds , is not a safe way of breaking it in . Use dummy rounds . Test fire with one round & inspect your spent brass for high pressure signs or case deformation & that the BCG is held back on last round from the Mag., then two , then three & if all is well fire to break in barrel , if you do that sort of thing . Edited August 29, 2014 by survivalshop Quote Link to comment Share on other sites More sharing options...
j.peace Posted August 31, 2014 Report Share Posted August 31, 2014 (edited) A couple of moths ago at the range a guy had a mossin nagant he was having problems with a tight chamber .He had a live round stuck in his chamber. Confused he went to chamber another round on top of the stuck round. Both rounds detonated causing a weapon explosion. Sending himself and the bystander behind him to the hospital via ambulance. Edited August 31, 2014 by j.peace Quote Link to comment Share on other sites More sharing options...
Owl21 Posted September 8, 2014 Author Report Share Posted September 8, 2014 I finally got some range time with the rifle. I was able to get about 50 rounds through it before I had to call it a day. So far, for the break in period, it runs fine. I had a few failures where the spent brass did not fully eject. I attribute these to not having the stock firmly in my shoulder. The accuracy is sub MOA, so far, when I do my part running FGMM 175 SMK. The only thing I cannot account for, is that the spent brass ejects about 2 to 3 feet forward and 20 degrees to the right. This does not change if suppressed. I am running a standard DPMS carbine buffer and a GL-Shock stock. Quote Link to comment Share on other sites More sharing options...
EasyEJL Posted September 8, 2014 Report Share Posted September 8, 2014 not bad. mine ejects about 8-10' at around 3 o clock. Its hazardous to be around me when I shoot. Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted September 8, 2014 Report Share Posted September 8, 2014 @Owl21, it looks like your cycling too fast still. Add some weight to your buffer/BCG. Quote Link to comment Share on other sites More sharing options...
Owl21 Posted September 8, 2014 Author Report Share Posted September 8, 2014 @Owl21, it looks like your cycling too fast still. Add some weight to your buffer/BCG. Thanks. That will be next. Quote Link to comment Share on other sites More sharing options...
sketch Posted September 8, 2014 Report Share Posted September 8, 2014 I'm running a RRA and my brass is always in front of the muzzel same spot after slashes heavy buffer. Quote Link to comment Share on other sites More sharing options...
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