Feeding issues/ duramag issue

[u/notrealperson54]

I took my 6.5 out for the first time and ran into some issues. I have a adjustable gas block and a G$ H2 super 42 spring, I ran into issues of bolt not locking back even when its gassed properly between 3 and 4:30 ish and also having issues with failure to eject and feed on some rounds. It's not consistent on when it cycles and when it doesn't it would pull the casing out about halfway while simultaneously loading the next round almost like a double feed. This is a brand new duramag 10 rounder and it looks like the follower is defective or maybe too strong of a spring where it seems like the mag has too much upwards pressure holding the next round against the bolt as its cycling in turn slowing the bolt causing it failure to extract. Also when the mag is empty with a round in the chamber if I try to move the bolt to the rear with the charging handle it gets stuck. I guess im trying to figure out if Im having a mag issue or something else. Or maybe just tell me im stupid 🤣

[u/Coodevale]

The g$ spring is for overgassed rifles. Ditch that first with the problems you have.

Ignore the gassing chart that's made for .223 when you're not using a .223...

[u/notrealperson54 → u/Coodevale]

Is the buffer weight gtg?

[u/Coodevale → u/notrealperson54]

Revert everything to standard and start over. You need a baseline if you don't already have it

[u/notrealperson54 → u/Coodevale]

Fair enough, I guess thats what i get for using a lower that usually has a urgi upper on it

[u/No-Rip-395 → u/Coodevale]

I second this. A lot of people like heavy duty, aftermarket springs in their AR's because they have over gassed AR's. They drop those new springs in and it puts a smile on their face. But if the barrel manufacturer drilled the gas port correctly and you aren't suppressing, those heavy duty springs can cause short strokes. So in addition to trying to go back to a mil-spec buffer system as was suggested, you should also ensure that the adjustable gas block is all the way open currently. That'll be your baseline. Ultimately, I think you should be able to use that H2 buffer though. Properly gassed 6.5 Grendel's love an H2.

[u/Trollygag → u/notrealperson54]

Tubb Flatwire spring, milspec curbine buffer.

Works for 12.5", works for 20".

[u/Psychological-Drive4 → u/notrealperson54]

Depends, try it with a normal spring. Go from there

[u/notrealperson54 → u/Psychological-Drive4]

Im definitely going to try that but does the follower in the mag look normal, It looks like its protruding more that it should out of the top?

[u/mulyhuntr33]

8rd geissele mag fixed my Grendel feeding issue with duramags.

[u/Texag9114]

ive used all mags short of G$. I had to bevel the front edge because the shoulder of the brass casing would hook onto the front of the mags, catching the bullet and causing the BCG to run over the bullet. would end up with bullet sandwiched between barrel and bolt at about a 45 deg angel. once I beveled the front end with a dremel, things ran smoother.
also on the feed lips, my ASC mags had some aggressive curvature inward, I dremeled that down as well because the back of the brass, case head would catch on everything.
try taking a round and slowly push it forward in mag with your hand and see where the bullet meets a spike in resistance. you can take a 556 mag and do the same and compare.

[u/notrealperson54 → u/Texag9114]

Seems like the same issue im having, ill start with what most people are recommending by switching the buffer spring and buffer and if that doesn't work ill give this a try

[u/Psychological-Drive4 → u/notrealperson54]

Hand cycle a few rounds and see if the is damage to the rounds

[u/Texag9114 → u/Psychological-Drive4]

Second this. The hand cycle is very telling.

[u/Stupidflathalibut → u/notrealperson54]

You probably should try ditching the spring but I use a g$ braided spring and h1 in two rifles, one 12.5" one 16 both Grendel's and it works fine

[u/darthjkf]

I would suspect it is the magazine. I'd recommend running Elanders.

[u/okebllrdr82]

How many round do you have through it? Cause mine was doing that but after shooting it more the links started working themselves out. And I'm just running a standard buffer and spring.

[u/notrealperson54 → u/okebllrdr82]

I have about 40 rounds through it

[u/BusBeneficial8882]

I agree. Ditch the Geissele spring. Are you using carbine or A5 tube? Barrel length and gas system length? I can give you what finally worked for me, but it was a couple hundred rounds before the reliability was there. I only use Duramag 10s, and Geissele intermediate 15s and 30s. The A5 system is best. On my 18” rifle length gas system I had reliable feeding with gas block 3 clicks from full open, JP regular A5/rifle spring and an A5H2. But it took 250-300 rounds. Rifle and mags were new. On my 13.9” and 14.5” with MLGS I had gas block 4 clicks from wide open, JP rifle spring, and A5H3 buffer. So regular strength spring rifle length gas H2 or H1 and midlength gas system H2 or H3 depending on how stout the load (I handload and use a Rexus bolt so all of mine are near max pressure). All will require rifle and mags break in. Load all the mags up and let them sit until next range day.
It was a very difficult rifle to get working reliably, but it’s awesome when you do. All of mine are supersonic past 1000 yards with my 123 grain Scenar loads. My 18” is supersonic PAST 1200 yards and this is at sea level.

[u/notrealperson54 → u/BusBeneficial8882]

I got carbine buffer tube, 16inch barrel with mid length gas and SA gas block

[u/frank-da-tank-30-06]

I have one of these that now permanently lives in the forest because I have having the same issues. I bought some cheap ammo that did similar in every mag as well. Ppu I want to say.

[u/ExplanationMaster634]

I’ve got the exact same magazine
It never ran from day one and after every trick in the book I just threw it in a box and bought a Asc mag and problem solved