6.5 Grendel Forum
Feeding issues with custom build - Printable Version

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Feeding issues with custom build - Flight Medic - 04-24-2020

FINALLY took my Grendel AR to the range on Monday to zero the scope and create a dope chart for Hornady Black ELD Match ammo. As soon as I loaded the first mag I was having feeding issues. The rounds are hitting low on the barrel throat and not advancing into the chamber, and I have to press up-and-forward on the bottom of the magazine while re-cycling the bolt to get the round to feed. Once I do that it feeds with no problem. My guess is the E-Lander magazines are not playing well with my Aero Precision lower, but its weird because I did NOT have this problem when I did the barrel break-in back in February. I used the same magazines and the same (brand of) ammo. The only difference was that the temperature outside was 35-degrees colder when I did the barrel break-in (40° vs 75°). Actually, there WAS one other difference...I had no scope mounted on the rifle for the barrel break-in, but I cant see as how that would affect the lower receiver.


Has anyone else here had feeding issues with either E-Lander mags or Hornady Black ammo? Could it be a problem with the magazine catch from the Geissele Lower Parts Kit I used?? I've ordered two new "AR Stoner" brand magazines from Midway USA...hoping that will fix the problem. In the case in doesn't, I guess I will try a different lower parts kit??

Thought and suggestions greatly appreciated.

Feeding issues with custom build - tdbru - 04-24-2020

Flight Medic,
hmm... i have E-Landers and have no issues, so far. my lower is an Anderson with a PSA lower parts kit and a BCA upper(kind of a Franken rifle). i don't have a lot of rounds downrange yet however. my biggest problem is extracting myself from work to get some range time......

did you happen to drop the magazine with it landing on the feed lips between barrel break in and sight in? do the feed lips on the magazines look like they got bent by a drop or something?
-tdbru

Feeding issues with custom build - Klem - 04-24-2020

If the mags have fed properly previously then unless you are trying a new bullet it is probably friction; concentrate on pushing every single round to the back of the mag as it only takes one or two rubbing against the front to slow that follower down. We don't have, or leave too much clearance in this calibre so it doesn't take much to load too long, or not have all rounds loaded properly. Knock that mag after loading and rounds will drift forward against the wall. I find this happens a lot with heavy Blackout rounds, and the heavier the bullet and the more you load, the more you need all that magazine strength.

Feeding issues with custom build - Flight Medic - 04-24-2020

The E-Lander magazines (two, 17-round capacity) are new, never been dropped. I was loading only 5 rounds at a time, so should not have been an issue with the springs. I tap the back of the mags on a solid surface after loading rounds so the cartridges are seated as far back (primer side) as they can go.

To me it seems the magazines arent seating up high enough in the magwell (since pushing up on the bottom of the magazine while sending the BCG forward eleviates the problem). There is NOT a lot of slop (wiggle) in the magazines once they're seated...no more than any other of my AR-15's.
But just the slightest upward force on the magazine will allow the round to feed. I just cant figure out why I did not see this issue during the barrel hreak-in...unless something in the lower receiver has shifted or loosened-up somehow after just 30 rounds(??).

So weird. Hoping its an easy (no-gunsmith-required) fix. If I have to, I will purchase a new lower...but, thanks to an insanely-tight fit and a handguard that required red Loctite on the barrel nut, I would need an acetylene torch and a breaker bar to remove the barrel, so replacing the upper receiver is out of the question at this point.

Feeding issues with custom build - Lastrites - 04-24-2020

Humm, having the same issue with the same mags and new Aero lower myself I recently put together, way less of an issue with c-product mags. Compared the mags, the rounds tilt much higher towards the business end, also seemed that the rib and the lip above near the shoulder was impeding the loading the as well. Took one E mag removed the lip, reworked the port side lip and it is working much better. Replaced the mag catch as well but that likely didn't do much, been wondering if the mag catch location is a smidgen low myself, need to measure.

Feeding issues with custom build - FLshooter - 04-24-2020

Try an ASC mag. I’ve only used one brand mag since I got into the 6.5 Grendel platform,ASC.I shot thousands of rounds through my three 6.5 Grendel’s. Never a feeding issue.

Feeding issues with custom build - VASCAR2 - 04-24-2020

Another simple mod which has helped people in the past is the ejector mod. Many times the ejector does not have beveled edge which inhibits the cartridge head from slipping under the extractor and sliding onto the breech face of the bolt. It is not a guaranteed fix but is a simple mod which might help feeding. This problem with the AR-15 is usually associated with cartridges which have a larger diameter case head than 5.56/223.

http://bulletin.accurateshooter.com/2014/08/ar-ejector-mod-for-improved-reliability-with-larger-cartridges/

Feeding issues with custom build - BluntForceTrauma - 04-24-2020

I would operate under the assumption it's the magazine before making any other alterations to the gun.

Easiest test is trying different magazine brand, then go from there maybe?

Feeding issues with custom build - RobertFL - 04-24-2020

I have a new Aero receiver with the recent 12" GB barrel. I have shot between 45 and 50 rounds. I have not had any feed problems, I am using ASC 10 round mags that I also have used in my other 6.5 Grendel rifle. When I first got the ASC mags I slightly adjusted the lips up a little and also polished the underside of the lips with 600 grit paper on a wood dowel. I had to do this before when I first got my 450 BM rifle. The underside of lips all had burrs on them. There is a tool for adjusting mag lips, I don't have one..

Feeding issues with custom build - Flight Medic - 04-25-2020

Thank you, gentlemen. Your input is greatly appreciated. I will order some ASC mags as well and update you on my results.

Feeding issues with custom build - RobertFL - 04-25-2020

I just looked and not all my 6.5 Grendel magazines are ASC, a couple of my mags are "C Products Defense" .. I did polish all of the lip undersides and adjust lips as needed.

Feeding issues with custom build - Flight Medic - 04-26-2020

RobertFL Wrote:I just looked and not all my 6.5 Grendel magazines are ASC, a couple of my mags are "C Products Defense" .. I did polish all of the lip undersides and adjust lips as needed.

When you say "adjust lips", what exactly are they requiring? Also, what did you use to polish?

Feeding issues with custom build - RobertFL - 04-26-2020

https://www.youtube.com/watch?v=La00Obx2QHo I use Stainless steel magazines. I had 2 issues, first the brass was getting gouged /scratched up from the magazine. second the SST bullet tips were hitting low on the ramp causing feed issues. To address the deep scratches and the friction from the scratching I wrapped 600 grit sand paper around a wood dowel (a wood pencil may work) and lightly sanded/polished the ends of the bottom of the mag lips where the ends were rough. That ended the excessive scratching of the brass and reduced the friction of the rounds leaving the magazine. to bring the point of the bullet a little higher up in the magazine I very slightly bent the last 3/8" of the mag lips up, doing that allowed the bullet tip to hit higher into the ramps. I had my 450 Bushmaster a year before i got my first 6.5 Grendel. A lot of guys had to tweak their 450 magazines and I saw the polishing and adjusting the lips over at the 450 Bushmaster web site.

Feeding issues with custom build - RobertFL - 04-26-2020

VASCAR2 Wrote:Another simple mod which has helped people in the past is the ejector mod. Many times the ejector does not have beveled edge which inhibits the cartridge head from slipping under the extractor and sliding onto the breech face of the bolt. It is not a guaranteed fix but is a simple mod which might help feeding. This problem with the AR-15 is usually associated with cartridges which have a larger diameter case head than 5.56/223.

http://bulletin.accurateshooter.com/2014/08/ar-ejector-mod-for-improved-reliability-with-larger-cartridges/

Thanks for the link. There is so much I need to learn about the AR platform.

Feeding issues with custom build - Flight Medic - 04-28-2020

RobertFL Wrote:<snip> to bring the point of the bullet a little higher up in the magazine I very slightly bent the last 3/8" of the mag lips up, doing that allowed the bullet tip to hit higher into the ramps. </snip>

I felt the underside of the feed lips on my mags, and they were as smooth as a baby's bottom...so I followed your example and bent the lips up ever so slightly and...

[Image: b7jPjN.jpg]


WORKED LIKE A CHARM!! The rounds are feeding and ejecting with nary a whimper...and WITHOUT having to push up on the bottom of the magazine!! So stoked it was such an easy fix.

Thank you, brother.

Dave

Feeding issues with custom build - RobertFL - 04-28-2020

Glad it was an easy fix. I was slow, careful and only went a tiny bit when I adjusted my mag lips.. I was afraid I would open them up to much and launch ammo out of them... Or double feed causing a jam.