BUmmedic Posted February 16, 2016 Report Share Posted February 16, 2016 Took my M5E1 build (all Aero parts unless otherwise specified) out yesterday for the first time: matched M5E1 ODG cerakote receivers with 15" M-Lok hand guard, 16" QPQ barrel, low pro GB, melonite gas tube, LPK, nitride BCG, A2 flash hider, carbine buffer kit, Troy BUIS, Magpul CTR/MOE grip/AFG, and some Ergo rail panels.One failure to feed in first 10 rounds, the remainder up to 60 fed, fired, and ejected. Ejection pattern pretty consistent in the 1:30-3:00 position, about 4-5 feet away. Used two types of brass factory ammo, both NATO FMJ - one mil-surplus and one ZQi Guardian. No reloads. I've shot this through my .308 20" rifle, which shows a pretty consistent 4:30-5:00 ejection pattern at same 4-5 foot distance. Brass was also showing extraction claw on some, ejector swipes pretty consistently, mild denting of case mouth on some of the ZQi, mild denting just below shoulder on a few from both batches. No blown/bulging/flattened primers that I could see. Have never fired a 16" .308, so recoil was definitely sharper (which is what I expected). Also appears that the cases are striking the rear of the ejection port opening and stripping some of the cerakote finish away. I contacted Aero and they suggested firing some heavier-grain .308 commercial ammo to compare, but it does kind of bother me that there may be an issue with this thing shooting run-of-the-mill FMJ. Is this something that I should worry about and troubleshoot? I've already gotten suggestion for an adjustable gas block from one of my buddies. I have no problem doing that, but don't want to fix what ain't broken, or miss something else that may be a bigger problem. Thanks in advance! Quote Link to comment Share on other sites More sharing options...
MikedaddyH Posted February 17, 2016 Report Share Posted February 17, 2016 You have to break in the 308 with a redickuless amount of lube. Running down your arm, splashing in your face ,dripping on the floor. WET ! Mobil ONE or Castrol GTX.Once you get past 100 rounds the gun should be good to go ! Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 17, 2016 Report Share Posted February 17, 2016 One FTF with a new build , sounds like she is working just fine . Spent Brass looks OK . What gas system length is your Barrel ? I also believe in the run them wet on break in ( well maybe not running down your arm ? ). Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 17, 2016 Author Report Share Posted February 17, 2016 Thanks for the responses, guys... I'm starting to think it's nothing to worry or right home about. I don't know about the "running down my arm" wet, but I use a healthy mixture of Rem-Oil and MPro7 on a soaked rag to wipe down all parts once they're clean... gets them nice and slick, before reassembling and wiping them down again and spraying them with Rem-Oil aerosol and putting it all back together. I've never had a problem, plus, I can take the aerosol with me to the range to spray down as I see fit during shooting, and before running a patch or bore snake for a provisional clean before packing up and heading home. I've never tried the Castrol or Mobil-1 treatment, but a lot of guys I know like it. Thanks again! Quote Link to comment Share on other sites More sharing options...
392heminut Posted February 17, 2016 Report Share Posted February 17, 2016 Wiping down with an oil soaked rag is not what these guys were saying. We've found that literally dripping with oil works the best, seriously! Quote Link to comment Share on other sites More sharing options...
shepp Posted February 17, 2016 Report Share Posted February 17, 2016 Wiping down with an oil soaked rag is not what these guys were saying. We've found that literally dripping with oil works the best, seriously!yup, cone tip mini squeeze bottle with Mobil one synthetic. Not quite running down your arm but a good helping apllied directly to parts from the bottle Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 17, 2016 Author Report Share Posted February 17, 2016 Wiping down with an oil soaked rag is not what these guys were saying. We've found that literally dripping with oil works the best, seriously!Oh, it gets sprayed down to dripping, wiped (great way to keep the rag soaked), and then sprayed again to dripping before being reassembled. It may not be dripping down my arm, but it's wet. Sorry if it came across as otherwise. Quote Link to comment Share on other sites More sharing options...
washguy Posted February 17, 2016 Report Share Posted February 17, 2016 Bu everything is fine....the the spent cases that are hitting the ejection port is fine...its what happens.. the anodizing on my rifles gets bruised too at the port lolWash Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 17, 2016 Author Report Share Posted February 17, 2016 I don't care so much about the port, it's the case head/ejector swipes and forward ejection pattern that initially got me questioning. The port wear was just an after-the-fact finding. I get that the cases are striking there and the deflector, which is what I expect them to do. Quote Link to comment Share on other sites More sharing options...
beantown Posted February 18, 2016 Report Share Posted February 18, 2016 Mobil One and a AR308 were made for each other. Wash turned me on to that trick. :thumbsup: My LR308 beats up brass also. I know I'd be beat up, if someone grabbed me by my ass, and ripped me out of a pipe backwards at Mach 1. Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 18, 2016 Author Report Share Posted February 18, 2016 Mobil One and a AR308 were made for each other. Wash turned me on to that trick. :thumbsup: My LR308 beats up brass also. I know I'd be beat up, if someone grabbed me by my ass, and ripped me out of a pipe backwards at Mach 1.Ha ha! Love it! Quote Link to comment Share on other sites More sharing options...
MikedaddyH Posted February 18, 2016 Report Share Posted February 18, 2016 LMAO !I wipe my elbow off then apply it to the gun !Lol Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted February 18, 2016 Report Share Posted February 18, 2016 I put a chunk of rubber grip tape on the deflector, it markedly decreased the case denting on both 7.62 and 5.56 rifles. I didn't care so much about finish wear but wanted to keep the cases as nice as possible for reloading. Quote Link to comment Share on other sites More sharing options...
unforgiven Posted February 20, 2016 Report Share Posted February 20, 2016 Blast away brother,you'r gonna love that rifle.I likey my M5. Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 20, 2016 Author Report Share Posted February 20, 2016 Blast away brother,you'r gonna love that rifle.I likey my M5.Thanks! Can't wait to get it back out there again! Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 21, 2016 Author Report Share Posted February 21, 2016 (edited) Saw these peening marks on the rear of the lower also on either side of the buffer. Cerakote is being stripped away a bit. Definitely impact marks. No noticeable damage to carrier body. Edited February 21, 2016 by BUmmedic Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 21, 2016 Author Report Share Posted February 21, 2016 Maybe I spoke too soon? Quote Link to comment Share on other sites More sharing options...
392heminut Posted February 22, 2016 Report Share Posted February 22, 2016 We've seen this before. The quick fix is to stack however many quarters in the bottom of your buffer tube it takes to keep the bolt carrier from making contact with the receiver. Problem solved! Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 22, 2016 Author Report Share Posted February 22, 2016 I saw that on another site. I actually took the buffer spring out, left the buffer in the tube, and dropped the carrier into the tube while holding the trigger down to get it out of the way to see if it would make contact. The carrier actually has several millimeters of play and does not make contact with the lower. I don't know where these marks could be coming from. I'm perplexed. Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted February 22, 2016 Report Share Posted February 22, 2016 The limits of travel in live fire may be different. 50 cents did the trick for me on my Matrix build. Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 22, 2016 Author Report Share Posted February 22, 2016 (edited) The limits of travel in live fire may be different. 50 cents did the trick for me on my Matrix build.But if the carrier doesn't contact the lower with only the buffer sitting in the tube, I don't see how live fire would allow it to go further and make contact unless every shot is allowing the buffer or tube to compress or elongate and plastically deform and rebound (I'm not a physics or engineering major, but something tells me a 7075 mil-spec tube won't do that). If it will, please someone school me... I've always been a good student. Edited February 22, 2016 by BUmmedic Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted February 22, 2016 Report Share Posted February 22, 2016 There is a bumper on the end of the buffer, maybe it compresses some. Could also be carrier tilt allowing contact, not sure but it sure looks like the dings I had on mine, I used an Aero tube as well and they are known for this issue. I notched my tube to get more threads engaged and secure the detent better as well, it was just captured by the tube and was leaning at an angle till I cut the notch for it. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 23, 2016 Report Share Posted February 23, 2016 Depth of inside Receiver Extension ? Length & Weight of the Buffer ? Length of Buffer Spring & how many Coils ? Quote Link to comment Share on other sites More sharing options...
BUmmedic Posted February 23, 2016 Author Report Share Posted February 23, 2016 Depth of inside Receiver Extension ? Length & Weight of the Buffer ? Length of Buffer Spring & how many Coils ?Best as I can measure:1. 7"2. 2.5" and 3.8 oz3. 11.25" and 27 coils Quote Link to comment Share on other sites More sharing options...
survivalshop Posted February 24, 2016 Report Share Posted February 24, 2016 7" is correct for a std AR 15 Receiver Extension ( Buffer tube ) & is used for DPMS type Carbines. 3.8 oz. Buffer is a little Heavier than the ones I have , but a good thing . 2.5" is correct for a DPMS Carbine length Buffer27 coils are two less then the normal 29 coils I have here with two Springs , but may be the way you counted . If the coil count is correct , the less coils may be an issue .11 1/4 " spring length is correct for a DPMS Carbine Buffer spring . I don't see what Gas system length you barrel has . It could make a difference , a Carbine gas system could cause a faster & longer Gas signature . The slight touching at the Extension headed area on the Lower Receiver could also be how the Receiver is made . If Buffer spring actually has only 27 coils , I would see if you could get another one to try , it doesn't take much to unbalance the system , if you are compressing the Buffer material on the end of the Buffer that much , that is a problem & stacking $$ in there is just putting a bandaid on to fix a larger issue with the Buffer system . If a New Spring doesn't take care of it , there is a a Company that is on this sight ' Heavy Buffers " who you can get a Heavier Buffer & his cut down AR 10 Spring that will should help slow the BCG down to stop it from hitting the Receiver. Quote Link to comment Share on other sites More sharing options...
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