m-4 feedramp issue


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HOLY DIVER
February 25, 2010, 10:36 PM
just got done building my new upper, and i have a issue with the feed ramps (i think). The barrel extension and upper reciver have m4 ramps.i chambered a round and ejected it and it had a pretty bad looking scar on the bullet it self. i'm thinking i need to remove the barrel and polish the 2 lug slots in the feed ramps?. i wanted to get some opinions before i started

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wally
February 25, 2010, 10:38 PM
Are you sure the mag is good and its not borderline nose down jam?

--wally.

HOLY DIVER
February 25, 2010, 10:42 PM
yep tested with 3 mags 2 pmags 1 colt all same result

Nugilum
February 25, 2010, 10:56 PM
http://i262.photobucket.com/albums/ii114/nugilum/postpics.gif

HOLY DIVER
February 25, 2010, 11:02 PM
ok good news it seems after i chambered about 20rds the scar seems to be the normal very light looking scar that all my AR'S leave on bullets.that makes me feel allot better. although the more i examine the bullets the scars on the bullets that came out of the pmags look to be even lighter. (all the more reason for me to buy more pmags!) so i guess chambering a few rounds knocked the sharp edge off the feed ramp.

HOLY DIVER
February 25, 2010, 11:03 PM
nugilum i took pics but i could not seem to get the focus right (you would not have been able to tell anything)

Zerodefect
February 25, 2010, 11:25 PM
That scar could be the bullet hitting the leading edge of the magazine. PMAGS feed alot smoother and quicker.

as long as the tip isn't deformed your fine. Pics needed.

Birddog1911
February 25, 2010, 11:33 PM
Every AR I've had would scratch up a cartridge, be it my old M16A2, or any of my civilian ARs. Pics really would be helpful.

MrCleanOK
February 26, 2010, 02:11 AM
Sounds normal to me.

Quentin
February 26, 2010, 02:11 PM
The round could be getting scratched by the extraction process, the ejector trying to kick out the cartridge and scratching the bullet on the barrel extension/bolt lugs. Can you slowly extract the cartridge and watch for that?

taliv
February 26, 2010, 02:14 PM
agree with quentin. it's not getting scratched going in. it's getting scratched coming out.

in other words, no problem

carbine85
February 26, 2010, 03:47 PM
Feed ramps or not, they get scratched. The feed ramps shouldn't have anything to do with it.

Gary G23
February 26, 2010, 05:07 PM
step away from the dremel tool

HOLY DIVER
February 26, 2010, 07:17 PM
no worry guys i have done nothing to my feed ramps lol!!!!!!!!!!!!!!!!! it was only the first five or so rounds i chambered that had deep scars it looks pretty normal now. i'm fixing to take some pics of my new build(upper) lower is not done yet and post them, i'm very excited about this White Oak Armament barrel i used

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