Failure To Feed due to magazine

[Vsaluki]

First attempt to post on this forum. Bear with me.

Just finished building my Grendel a couple of days ago. My first attempt to fire a round resulted in two failures.

It uses an Odinworks 20" barrel, and Odinworks BCG, and Aero Precision upper & lower. C Products Defense magazines.

For my first attempt I loaded a single round into the magazine and tried to chamber it by pulling & releasing the charging handle. It jammed with the bullet stuck above the barrel extension & the bolt against the side of the case. I pulled the magazine and the round, reloaded the magazine, locked the bolt back, inserted the magazine, and hit the bolt release. It chambered fine.

After firing the round, I found the shell case laying on top of the magazine. The bolt was locked open. I repeated the entire experiment with a second round and exactly the same result. Rather than playing further with a dangerous situation, I loaded up a squib.

I then loaded the squib into the magazine and the magazine into the rifle with the bolt closed. I then used the charging handle and slowly pulled the bolt back and slowly rode it forward. What I saw was that the bolt passed over the rim of the cartridge, but then caught the edge of the extractor grove. With the bolt caught in the extractor grove it pulled the round forward, but the back of the round could not rise up because the rim was under the bolt. With the back trapped, the front of the round moved up steeply and ended in the jammed position that it previously experienced.

I did the experiment a second time and noticed that the round was slightly tilted in the magazine when I tried to load from a bolt closed position, but not when I tried to load from a bolt open position. I believe that the bolt depresses the round as the charging handle is pulled back, and the rim is the last thing that is depressed as the bolt clears the round. But the C Products magazine was not returning the round to level at that point.

I also found that I could simply press down with my finger on the head of the single loaded round, and it would remain tilted within the magazine. See photo of tilted and untilted rounds below. I tried the same trick with a 260 round in my AR10 Pmag and the round always returned to level. I would think that anyone on the forum with the C Products Grendel mag could repeat this test (thumb press only) with a single round in the magazine and get the same results.


image.jpgimage.jpgimage.jpg

[1075 tech]

My first impression is that the follower is sticking. Did you clean the mags? Sometimes new mags come with some gunk in them.

[VASCAR2]

I've seen brand new mags where the springs have not taken set cause issues. If I were in your shoes I'd disassemble the mag and clean the mag body, spring and follower. While you have the mag apart inspect the follower for any excess plastic from the molding process and remove. I'd reassemble the mag and load it to full capacity and let it sit loaded for a few days to allow the springs to take set. Make sure the mag spring is installed in the mag correctly upon reassembly. After doing this to the mag and all mags still fail to function I'd contact the manufacturer.

If you have a good 223/5.56 mag you can load two or three rounds and see if the rounds function in your 6.5 Grendel. The 6.5 Grendel cartridges will usually function out a 223/5.56 mags until you load enough Grendel rounds the case taper starts to interfer with the rounds stacking in the mag.

[Vsaluki]

Ftf

Thanks guys. I did not clean the magazines, but will give that a try. I was considering also polishing the inside area just below the lips with a dremmel & some Flitz. When the mag is unloaded I can feel a fair amount of force at the top by the follower. But it seems to be the friction caused by the follower pushing the case against the side that is making it stick in a tilted position.

[Vsaluki]

So I thoroughly cleaned the mags and even polished the interior surface where the followers were hanging. It made no difference. The C Products mags are just poorly made. As an experiment I tried pushing down on just the front of the follower of the C Products mags and then I did the same with a Pmag. I noticed that the C Products mag tilted about three times as far as the Pmag before the back of the follower moved down with the front. Having taken the C Products mag appart, I noticed that the follower was not very deep where it extended into the magazine. This would make it easier to tilt. A deeper follower would force the magazine to be longer, however, it would resist tiling more. I also noticed that there was much less slop with the Pmag with regard to how snuggly it fit around the peremiter of the follower.

I'm sure there are other people on this forum that have both 10 round Pmags and 10 round C Products mags. I would appreciate if someone else repeated my little tilt experiment and let me know if my results are unique or common. Incidentally, the Pmag that I was using for comparison was from my .260 AR10.

[1075 tech]

I've seen brand new mags where the springs have not taken set cause issues. If I were in your shoes I'd disassemble the mag and clean the mag body, spring and follower. While you have the mag apart inspect the follower for any excess plastic from the molding process and remove. I'd reassemble the mag and load it to full capacity and let it sit loaded for a few days to allow the springs to take set. Make sure the mag spring is installed in the mag correctly upon reassembly. After doing this to the mag and all mags still fail to function I'd contact the manufacturer.
.

Did you do this?^^

[oldbarnowl]

When I first started building my 65G I acquired some 10 rnd Cproducts mags, with blue follower. I found that the spring pressure was seriously lighter than those I have purchased since. I found that I could stretch the springs to 50% more length, temporarily increasing their push. That improved it . Replacing the springs fixed those 3 mags I started with. You might even put 15 round springs in a 10 rnd mag.

http://www.ammosc.com/10-round-6-5-spring-kit/

[Vsaluki]

When I first started building my 65G I acquired some 10 rnd Cproducts mags, with blue follower. I found that the spring pressure was seriously lighter than those I have purchased since. I found that I could stretch the springs to 50% more length, temporarily increasing their push. That improved it . Replacing the springs fixed those 3 mags I started with. You might even put 15 round springs in a 10 rnd mag.

http://www.ammosc.com/10-round-6-5-spring-kit/

Thanks for the suggestion. I think that I will order those springs and followers. It looks like C Products simply chopped off a piece of the follower on the neck side of the cartridge in order to create the extra space for the Grendel rounds. This would save them the expense of manufacturing a longer 10 round magazine body. But the shortened follower would also tilt more easily. I'm guessing that they are also using unmodified 5.56 springs. And if they didn't change the magazine or follower in any other way, it would also mean more sideways crowding and more pressure of the Grendel rounds against the side of the magazine, thereby producing more of a tendency for the round to stick. In any case, here are a couple of photos of what I found in the magazine. The chopped off part was done by C Products, not by me.

image.jpgimage.jpg

[Vsaluki]

Thought I would post my final solution to the problems of the tilting C Products follower described above. After failing to fix the tilt problems by polishing the interior of the mags to get rid of any rough or hanging locations, I still couldn't get the mags to work correctly. My next step was to order a couple of the E-Lander 10 round mags from Alexander arms. When they arrived I experimented with them to see if I could get the same follower tilt as with the C Products, but I could not.

I took the springs out of the E-Lander mags and compared them to the C Product mags and found that the E-Lander springs were longer & stronger. So I tried the E-Lander springs in the C Product mags, but the tilting problem remained. Wanted to try the E-Lander followers in the C Products mag also, but they would not quite fit.

In any case, the E-Landers fixed my failure to feed/jamming problem.

So, here's a little additional info. I was able to get 10 rounds into the 10 round E-Landers, but I could not get the mags to lock in on a closed bolt. however, 9 rounds seem to lock in comfortably. Also, the strong E-Lander springs require a fair amount of force to get the bullets loaded. When unloading the mags by hand, I notice that the bullets had a tendency to catch on the side groves and hang a little, but this has so far caused no feeding issues. Still, I may go ahead and experiment with smoothing the inside of those down a little with a dremmel.

Alexander arms asks quite a bit more for their E-Landers than other sites that I found carrying the E-Lander mags. And they have a steep shipping fee. However, the other sites that sell E-Lander don't carry the Grendels. So, if you are have mag problem, I suggest paying the extra to get rid of them is worth it.

[NugginFutz]

...Alexander arms asks quite a bit more for their E-Landers than other sites that I found carrying the E-Lander mags. And they have a steep shipping fee. However, the other sites that sell E-Lander don't carry the Grendels. So, if you are have mag problem, I suggest paying the extra to get rid of them is worth it.

Glad you sorted out your issue.

Sometimes it just pays to spend a little extra for known quality. If you pro-rate the time you spent on troubleshooting the C-Product follower issue, you could have likely bought at least one more E-Lander.

My rifles all work well with 10-rd ASC or 17-rd E-Lander mags. While I don't have the 25-rd E-Landers, I would not hesitate to do so when I might need them.

As far as your inability to seat a fully loaded magazine under a closed bolt is concerned, it may become easier as you go through several load/unload cycles with it. I know mine seemed to.

[Mopardoctor]

I had the same problem with my C-Products mags. They would load from a open bolt but would have a FTF jam when the bolt is pulled back and released. I noticed that the top round is sitting more of a angle rather than the way they lay in a ASC mag. I took a hammer and gave the front of the left feed lip a couple of taps to put the top round in a more level position and I have had no more FTF with a manual load.

Mopar Doctor
Got Ammo?

[Vsaluki]

I had the same problem with my C-Products mags. They would load from a open bolt but would have a FTF jam when the bolt is pulled back and released. I noticed that the top round is sitting more of a angle rather than the way they lay in a ASC mag. I took a hammer and gave the front of the left feed lip a couple of taps to put the top round in a more level position and I have had no more FTF with a manual load.

Mopar Doctor
Got Ammo?

Thanks for the update. Along with having the E-Lander magazines work correctly, I found that replacing the C-Products follower & spring with the ASC follower and spring also worked. C-Products seems to have chopped one side of the follower legs more than they should have, and that allows for the tilt. ASC has the same follower, but they chopped the legs less than C-Products, so there is still enough to keep the follower level. I think the objective of chopping the follower legs was to create the extra room needed by the 6.5 Grendel brass over 5.56 brass while retaining the same magazine length. C-Products just overdid it a little and so defeated the point of the follower legs.