AR15 Feeding Problems

[Phil3]

I built my first AR15 and have run into some feeding problems. The C-Products mags are questionable, as only one of the three I have even slides into the gun (the other two begin to jam up on insertion). With the one mag I have, two things happen. Failure to strip from mag. I pull the trigger and click, no round in the chamber. Secondly, a round does strip but is cocked trying to go into the chamber, and the bolt end is jammed against the brass, leaving it dented. Now here is the weird part.

Things generally work pretty reliably with PMC Bronze 55 grain FMJ ammo. BlackHills remanufactured ammo in 55 grain FMJ gives me all sorts of problems, rarely making it through one mag without trouble. This makes me wonder if it is the mag, or perhaps the bolt not returning far enough back to reliably strip a round due to ammo pressure. The bolt is a Young Mfg bolt, that is 1/2 oz heavier than normal.

I have been told to get USGI mags (how to get a 10 round in CA), or MagPul rebuild kits for the P-Mag. I can do that, but just hope I am not trying to solve a problem due to something else.

Thoughts?

- Phil

[Desert_AIP]

Did you build the upper or was it built by a vendor?

Do you have M4 feed ramps on both the upper receiver and the barrel extension?

Is everything lubed well, wet?

Can you insert the magazines when loaded to only 9 rounds or with the bolt locked back?

[Phil3]

I built the entire gun. I do not think the upper receiver has M4 feed ramps. It is SunDevil. Will need to check (can't get to rifle right now). All is well lubed. I can load the mag with less than 10 rounds, will need to try with 9 exactly. Mag goes in fine with bolt locked back. Have to push it in briskly to make it latch. Sometimes I notice though that the rounds do not look like they are positioned properly before the bolt closes, and then if I recall correctly, a round will not be stripped. It is like the rounds are too low in the bag. I need to watch this more carefully.

- Phil

[troysland]

Check to see if the feed lips on the C-products mags are bent. This can cause the rounds to get "hung" up and you won't be able to strip a round smoothly. You won't see that problem with p-mags as they have the strong polymer construction.

[Darklyte27]

Which range you going to Livermore? Chabot? Concord *USI* ?

[Reconsnake]

As stated above, try different quantities in each of the magazines. I have the best performance from magpul pmags, and use them almost exclusively now. The weight difference with your bolt will most likely not be your issue. Verify the buffer and buffer spring are correct length for your stock ( rifle length parts are longer than carbine/collapsible ones ). Manually charge the weapon, verify there is clearance for the bolt face to grab a round. Recently, there was a run of out of spec carbine length buffer tubes, which with the correct parts, was not milled deep enough to allow the bolt to come all the way back.

[Phil3]

Which range you going to Livermore? Chabot? Concord *USI* ?

Primarily Chabot. For longer range, I go to Sacramento, but this is rare given the 2 hour drive to get there. - Phil

[phish]

How many rounds through the gun so far? It took me about 200 to get things to work smoothly after putting on a new barrel. Check your bolt to see if it has that funky green fouling, that stuff can really gum things up.

[Darklyte27]

There will be quite a few calguners out at chabot day after thanksgiving, if i go ill be happy to take a look if you are still having problems.

[Phil3]

How many rounds through the gun so far? It took me about 200 to get things to work smoothly after putting on a new barrel. Check your bolt to see if it has that funky green fouling, that stuff can really gum things up.

About 200 - 250. Don't know for sure until I get home and check my notes.

No green fouling. Everything seems to work smoothly.

- Phil

[Phil3]

There will be quite a few calguners out at chabot day after thanksgiving, if i go ill be happy to take a look if you are still having problems.

Thank you. Not sure I will be there on that day, but I am the older guy (50s), 6' 1", a crew cut on what hair I have left, and the AR is one with a rounded forearm with no rails on it. I will have a notebook out taking notes.

Appreciate the help if I run into you.

- Phil