I just recently built a 9mm upper using CMMGs radial delayed bolt and barrel, using CMMG branded MEAN Endomags. I have not shot it extensively yet. Put 30 rounds through it on my M16 lower and 30 rounds on a pistol lower, using same mag. Out of the 60 rounds of factory ammo, I had three misfeeds, where the round did not enter chamber square and ended up getting smashed by bolt. Two were on M16 with MGI buffer, one was with pistol lower and standard carbine buffer. Anybody else see these issues ? I know Amphibian has extensive experience with these setups, but don't recall reading about this problem . Really hoping I can get this resolved.
MEAN Endomag misfeeds
- Thread starter Roklok
- Start date
Here is some old test info when I first got my CMMG RDB: http://www.c3junkie.com/?page_id=90
I got the CMMG Glock lower to use as my baseline and this was also before the Endomags were on the market.
I tried the MGI buffer and it wouldn't lock the bolt back and I felt it was bouncy.
Standard buffer worked but I was getting a very high cyclic rate and I think also getting bolt bounce.
What factory ammo did you try? Remington is weak stuff. Some ammo that has a short COL will have issues like you describe.
That happens in my video here:
Zero malfunctions w/ various HP's but some very conical shaped soft tips rounds with a short COL jammed just like you mentioned.
Make sure your buffer spring isn't too strong. Standard power if you running a standard round spring....however I prefer the Tubb flat springs.
My preferred configuration is documented here: http://www.c3junkie.com/?page_id=280
BUT...I would recommend to test with a standard buffer and spring initially to make sure you don't have an out of spec carrrier, bolt or barrel before deviating from the CMMG recommended configuration in case you need to send anything back for RMA.
I got the CMMG Glock lower to use as my baseline and this was also before the Endomags were on the market.
I tried the MGI buffer and it wouldn't lock the bolt back and I felt it was bouncy.
Standard buffer worked but I was getting a very high cyclic rate and I think also getting bolt bounce.
What factory ammo did you try? Remington is weak stuff. Some ammo that has a short COL will have issues like you describe.
That happens in my video here:
Zero malfunctions w/ various HP's but some very conical shaped soft tips rounds with a short COL jammed just like you mentioned.
Make sure your buffer spring isn't too strong. Standard power if you running a standard round spring....however I prefer the Tubb flat springs.
My preferred configuration is documented here: http://www.c3junkie.com/?page_id=280
BUT...I would recommend to test with a standard buffer and spring initially to make sure you don't have an out of spec carrrier, bolt or barrel before deviating from the CMMG recommended configuration in case you need to send anything back for RMA.
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My experience with 9mm SB ammo has always been good. Early on some said that the Endomags needed a break in. I sometimes had issues where it just wouldn't feed...no round in the chamber but still had rounds in the mag. I haven't encountered that in a long time. Haven't had the misfeed problem you describe unless using short COL ammo or too heavy of a buffer or spring. I assume you are not using a carrier weight?
No, not using carrier weight. BCG as sent from CMMG. I am using a standard BCM upper receiver and have not enlarged the ejection port yet. Ejection seems fine and consistent, and I see no brass marks on edges of port. I know CMMG uses an enlarged port for 9mm but not sure its neccessary.
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