FearlessFreep Posted November 8, 2019 Report Share Posted November 8, 2019 Hello, I have finished my first .308 AR build and it has feeding problems, hopefully someone here can help. It's an Aero Precision M5E1 complete upper, 20" barrel. DPMS compatible 80% lower, Aero Precison LPK, Aero Precision BCG and charging handle. The buffer, spring, and receiver extension are all from Heavy Buffers, it's an AR10R-XH buffer, EA1095 spring, and rifle-length extension. The stock is a Magpul PRS Gen 3. So the problem it has is that when a 20 round mag is loaded with more than about 10 rounds, the round fails to feed. The round will end up about halfway out of the mag and pinched in between the bcg and the chamber, I have attached some pictures so that you can see what I mean. With 10 rounds or less it seems to be happy and has no feeding problems. I have tried Magpul Gen 3 magazines and also Lancer L7 magazines and they both experience this problem. I have tried Sellier & Bellot 147gr NATO rounds and I have also tried some hand-loads that I am not sure of the specs, and both types of rounds experience this problem. I am also seeing what I think are lots of brass flecks in the chamber. Any suggestions? Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted November 8, 2019 Report Share Posted November 8, 2019 Can’t tell for sure from the pictures, is it hanging up on the feed ramps, catching on the extension lugs? Could be the extra pressure from the magazine spring when loaded up is keeping the nose from coming up a little and clearing the lugs, could be a tolerance issue between upper and lower adding to the issue. I have seen something that looked like that in an AR-15 build , a little smoothing around the ramps solved it. Quote Link to comment Share on other sites More sharing options...
FearlessFreep Posted November 8, 2019 Author Report Share Posted November 8, 2019 Well now that I have done some more manual feeding from the Magpul mags, the rifle seems to be liking those mags just fine (no feed problems through 60 or so rounds cycled through by manually operating the bolt, whereas at first I was lucky to get two consecutive rounds to feed properly). The Lancer L7 mags are still exhibiting the feed problem I described so maybe my rifle just doesn't like the Lancers, I don't know. The Lancer mags do seem to be a lot stiffer than the Magpuls though, with that metal reinforcement at the top of the mag. Guess I'll take it to the range again and see if it feeds properly now with the Magpul mags when actually firing rather than just manual operation. Quote Link to comment Share on other sites More sharing options...
Armed Eye Doc Posted November 8, 2019 Report Share Posted November 8, 2019 Make sure to lube it well during break-in. Sometimes it just takes a while to get the parts to mate together properly. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted November 9, 2019 Report Share Posted November 9, 2019 (edited) This is a new gun. I'm sure those mags are new, too. They need broken in just like the gun does. Load all your mags to the top, FULL, and let them sit for a few days. Cycling live ammo into the gun, and manually extracting it - that's what's leaving the brass flecks. Bet your brass is marked up, too, with lines in it. That's the ejector, pushing the brass to the side, and the brass getting eaten up by the inside edges of the barrel extension. That'll happen alot less during live fire, and then happen even less once the gun is broken in. Edited November 9, 2019 by 98Z5V Quote Link to comment Share on other sites More sharing options...
FearlessFreep Posted November 9, 2019 Author Report Share Posted November 9, 2019 Thanks guys for the suggestions. I guess it may just be a break-in issue that will correct itself with time, as people here are suggesting. I just got a little bummed out when I had this brand new beautiful rifle and it wasn’t working right, but I guess I may have overreacted. Time will tell. I went ahead and cleaned it again and applied Break Free liberally, and I filled each mag completely full. BTW I did shoot it last week, that’s the first time I shot it and that’s when it began having the feeding problems. But when it did work properly it was very nice and pretty darn accurate too. I still have to get my scope zeroed. Quote Link to comment Share on other sites More sharing options...
mrmackc Posted November 10, 2019 Report Share Posted November 10, 2019 (edited) FF I'm sorry but I couldn't jest let this thread quietly slip by Help needed with feeding problems But when I have a bad day and have feeding problems I am apt to put a nice briskit with some special rub and a couple of tatters and corn on the cob on the GMG and go inside and pop a cap or two, on a cold brewski, that is!😝🎸 Edited November 10, 2019 by mrmackc Quote Link to comment Share on other sites More sharing options...
FearlessFreep Posted November 17, 2019 Author Report Share Posted November 17, 2019 Hey folks I just wanted to follow up on this problem I was having, it turns out that the problem was mainly the Lancer magazines. I spoke with tech support at Aero Precision and they said that Lancer mags do not work well with their rifles. They recommend Magpuls. Anyway I followed 98Z5V's suggestion of keeping the mags fully loaded for a few days and the rifle is doing great now, no problems (when using the Magpul magazines). Quote Link to comment Share on other sites More sharing options...
98Z5V Posted November 17, 2019 Report Share Posted November 17, 2019 (edited) 1 hour ago, FearlessFreep said: Hey folks I just wanted to follow up on this problem I was having, it turns out that the problem was mainly the Lancer magazines. I spoke with tech support at Aero Precision and they said that Lancer mags do not work well with their rifles. They recommend Magpuls. Anyway I followed 98Z5V's suggestion of keeping the mags fully loaded for a few days and the rifle is doing great now, no problems (when using the Magpul magazines). That is oddly strange, from them. I have Lancers that run great in the AP guns that I have. Most of my .308ARs are AP guns, too. I'll function test these things next time I get out there, Lancer Mags vs. AP guns. For everyone else out there - mags need a "break-in" too, just like these Big ARs need a break-in. Food for thought, in the future... Edited November 17, 2019 by 98Z5V Quote Link to comment Share on other sites More sharing options...
mrmackc Posted November 20, 2019 Report Share Posted November 20, 2019 You should have told them you were using their own mags. Give them something to think about for a while. Quote Link to comment Share on other sites More sharing options...
jtallen83 Posted November 20, 2019 Report Share Posted November 20, 2019 On 11/16/2019 at 8:34 PM, FearlessFreep said: I spoke with tech support at Aero Precision and they said that Lancer mags do not work well with their rifles. The last AP build I did has issues dropping the Lancer mags free on the last shot, still need to get more rounds on the combo before I can say much though. I had issues with Lancer's in a Matrix build but it was two specific mags that had different dimensions than the others, Lancer replaced those without a question. Hit them up and see what they say, bet they will want to know. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted November 21, 2019 Report Share Posted November 21, 2019 (edited) This is also an 80% lower that we're talking about - I just caught that. Everything that's going on here needs to have measurements in that 80% lower, confirmed to a full-production (functioning) lower, or we're wasting our time here. Mag catch height is first. Been down this road. That's not part of the 80% machining process, so it has zero to do with anything that the OP did during his machining. That doesn't mean that this 80% company didn't fuk that up - as we've seen all too well before. OP - you need to mic that lower out against a known functional, quality lower. Edited November 21, 2019 by 98Z5V Quote Link to comment Share on other sites More sharing options...
FearlessFreep Posted November 21, 2019 Author Report Share Posted November 21, 2019 Guys I'm sorry but this is the only lower I have, 80% or otherwise. I don't have anything to compare it to. FWIW, the lower was bought from 80 Percent Arms, don't know what their reputation is like among this community. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted November 22, 2019 Report Share Posted November 22, 2019 Then, we're stuck with suggestions. We can't go any further without numbers on your lower, compared to a factory lower. We've seen some severe mag-catch height issues in other 80% guns, that caused feeding problems. That started a whole thread about mag-catch height, and it's here somewhere. Sorry, man. Quote Link to comment Share on other sites More sharing options...
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