Warning

 

Close
Confirm Action

Are you sure you wish to do this?

Cancel Confirm
AR15.COM
AR Sponsor
12/9/2010 9:35:39 AM EDT
I am in the middle of nowhere on mobile.  A friends AR is not feeding right.  The bullet is wedging in the cuts in the feed ramp.  Happens both sides. Tried 2 different mags, one is new pmag..  the upper is Armalite .  Any ideas, he wants to go pig hunting.
Thanks

Posted Via AR15.Com Mobile

12/9/2010 9:39:08 AM EDT
[#1]
I would guess that his upper has M4 feed ramps and his barrel doesn't.  Post a picture of the feed ramps when you have a chance.
12/9/2010 9:48:04 AM EDT
[#2]
I will try to take a pic with my phone.  The complwte upper was bought from Armaliteasr year.

Posted Via AR15.Com Mobile
12/9/2010 7:16:19 PM EDT
[#3]
Inside of the edges of the feed ramps look sharp. possibly cutting into the bullet and grabbing it
12/10/2010 3:23:29 AM EDT
[#4]
You think the good old Dremel is the answer?
12/10/2010 3:36:26 AM EDT
[#5]
Could be the bullet wedging in the feed ramp tips, or could just be the hammer catching the FP collar.

When the problem happens, can he use the forward assist to get the round to load, or is the B/C completely locked up?


A photo of the Bullet tips after such a jam, and maybe a photo of the FP retainer pin and top of the hammer of the L cut would give up a better idea.
12/10/2010 5:38:00 AM EDT
[#6]
Like Dano said it could be the hammer catching the firing pin collar.

Something is definitely slowing and/or stopping the carrier from slamming home.

He's not riding the charging handle by chance is he?
12/10/2010 12:05:00 PM EDT
[#7]
The bullet is wedging in the feed ramp tips, tightly.   I tried it myself several times, both using the charging handle and by releasing the bolt stop and letting is slam forward on it's own.  The forward assist doesn't help because the bolt doesn't come near closing.  I will check the hammer theory when I get home from work.  I have an extra trigger group at home so I might change them out & see what happens.
12/10/2010 12:09:33 PM EDT
[#8]
Get the jam, then pull the mag straight down out the well to clear the round from the rifle, which should allow the bolt to slam home.

If the bolt stays in the half way forward position back, you can almost bank that the hammer has caught the FP collar.
12/11/2010 9:06:59 AM EDT
[#9]
Quoted:
Get the jam, then pull the mag straight down out the well to clear the round from the rifle, which should allow the bolt to slam home.

If the bolt stays in the half way forward position back, you can almost bank that the hammer has caught the FP collar.


Does that only happen with the older bolts where the fp collar is exposed? With an auto bolt the fp is shrouded.  Which bolt does he have?
12/11/2010 1:33:54 PM EDT
[#10]
Download your mags to 28 rounds and try a new action spring.

I had a simular problem and it was caused by a weak LMT action spring.
12/11/2010 8:00:32 PM EDT
[#11]
Quoted:
Quoted:
Get the jam, then pull the mag straight down out the well to clear the round from the rifle, which should allow the bolt to slam home.

If the bolt stays in the half way forward position back, you can almost bank that the hammer has caught the FP collar.


Does that only happen with the older bolts where the fp collar is exposed? With an auto bolt the fp is shrouded.  Which bolt does he have?


The exposed (non-protected) firing pin bolt carriers,,,yes. The notched hammer catches on the firing pin collar, will certainly happen if you have a M16 firing pin instead of the AR15 (smaller collar).

A good idea to build with the protected (full auto style) bolt carrier :)
12/12/2010 9:08:52 AM EDT
[#12]
try this link...

http://www.ar15.com/forums/topic.html?b=3&f=66&t=517575
12/12/2010 9:40:27 AM EDT
[#13]
Check this one out also...

http://www.ar15.com/forums/topic.html?b=2&f=145&t=195676

eta-if somebody can figure out how to make a link work
12/12/2010 10:27:07 AM EDT
[#14]
Quoted:
Check this one out also...

http://www.ar15.com/forums/topic.html?b=2&f=145&t=195676

eta-if somebody can figure out how to make a link work


Like this?
12/15/2010 8:58:07 PM EDT
[#15]
new magazine huh?

does the bolt gouge the top of the case also?
my guess is that the mag is not feeding properly
12/17/2010 8:04:06 AM EDT
[#16]
If the problem is not one that was always there Id try a new Mag but if it is consistent then I would clean the gun and gently polish the feed ramps since in the Pic they look out of line and not blended in.... Also Id try the upper on a diffrent lower to make sure its not a Trigger problem....Good luck and Good Hunting.....
12/17/2010 8:11:08 AM EDT
[#17]
What kinda ammo?
AR Sponsor