Bad m4 feed ramps advice on repair?

[jtorbin88]

So the car shoot in April I broke out the AR I built in December. It consists of a lower I built myself that functions perfectly. Now the complete upper I bought the rounds are jamming on the m4 feed ramps and sometimes even denting them pretty badly not sure what to do to fix this problem?

 

[jasons]

Feeding issues in ARs are more often than not really magazine issues. I'd try a known good magazine first.

You have a picture of the feed ramp area? Is there a "bump" where the receiver meets the barrel extension?

 

[jtorbin88]

Feeding issues in ARs are more often than not really magazine issues. I'd try a known good magazine first.

You have a picture of the feed ramp area?

I've tried pmags that worked perfectly in cekims full auto. Also have tried c products mags as well I have 6 30 round mags none of them feed reliably

 

[icyclefar]

looks to me like your barrel was not cut for feed ramps

 

[jasons]

View attachment 70124

I've tried pmags that worked perfectly in cekims full auto. Also have tried c products mags as well I have 6 30 round mags none of them feed reliably

Do you have a picture that's in focus?

 

[jtorbin88]

Do you have a picture that's in focus?

I only have my phone and its difficult to get a good picture, the aluminum part of the upper not the barrel nuts feed ranp isn't flush with the uppers and there hanging up there.

 

[jasons]

I only have my phone and its difficult to get a good picture, the aluminum part of the upper not the barrel nuts feed ranp isn't flush with the uppers and there hanging up there.

All you can really do then is clean it up with a round file and polish.

 

[jtorbin88]

All you can really do then is clean it up with a round file and polish.

That's what I figured, where can I get a round file that should be the right size?

 

[jasons]

That's what I figured, where can I get a round file that should be the right size?

I bought a set of various sizes at a generic hardware store. Most likely Lowes but I don't remember for sure.

 

[jtorbin88]

I bought a set of various sizes at a generic hardware store. Most likely Lowes but I don't remember for sure.

Appreciate it, any advice on wether I should buy a geissele trigger I've been going back and forth trying decide if its worth it lol.

 

[jasons]

Appreciate it, any advice on wether I should buy a geissele trigger I've been going back and forth trying decide if its worth it lol.

I have four of them, so you could say I'm a fan. Best AR trigger you can buy in my opinion.

 

[jtorbin88]

I have four of them, so you could say I'm a fan. Best AR trigger you can buy in my opinion.

I've got some money burning a hole in my pocket, my gf said no more gun til I buy a safe lol. So I'm looking at decking out the guns I have lol. I have a 3x illuminated 300$ sig scope but I'm considering getting an eotech for cqc.

 

[jasons]

I've got some money burning a hole in my pocket, my gf said no more gun til I buy a safe lol. So I'm looking at decking out the guns I have lol. I have a 3x illuminated 300$ sig scope but I'm considering getting an eotech for cqc.

I have an Eotech and an Aimpoint and I like the Aimpoint much better. I guess it depends on what you're doing though.

 

[Fixxah]

Dremel is easier than a file.

Natuonal Match Trigger from Joe Bob's is a nice two stage for the money. I don't have any gieselle or timney triggers in my ARs but may some day.

-Trolling via S3.-

 

[ColdDayInHell]

Where is the barrel from?

 

[jtorbin88]

Dremel is easier than a file.

Natuonal Match Trigger from Joe Bob's is a nice two stage for the money. I don't have any gieselle or timney triggers in my ARs but may some day.

-Trolling via S3.-

I heard single stages are great but not a combat reliable trigger. I hear geissele are the most reliable so reliable military special forces use them.

 

[jasons]

Dremel is easier than a file.

Natuonal Match Trigger from Joe Bob's is a nice two stage for the money. I don't have any gieselle or timney triggers in my ARs but may some day.

-Trolling via S3.-

The Rock River is a decent but inexpensive two stage as well, but I've known of two that have gone full auto after they wore out. I guess that could be a good thing or a bad thing depending on your perspective.

 

[Terminator03]

I would recommend the SSA model. There is an SSA-E model too, but from everything I have read, the SSA is better suited for all around use and HD. Apparently the "E" version is too light for some, and for that reason they say it is not the best choice for a duty or HD gun. The regular SSA is perfect inmo for everything and has a nice light and clean 2 stage break. It definitely spoiled me! The Eotech is a great choice for the close quarters stuff, or also consider the Aimpoint PRO.

 

[jtorbin88]

I would recommend the SSA model. There is an SSA-E model too, but from everything I have read, the SSA is better suited for all around use and HD. Apparently the "E" version is too light for some, and for that reason they say it is not the best choice for a duty or HD gun. The regular SSA is perfect inmo for everything and has a nice light and clean 2 stage break. It definitely spoiled me! The Eotech is a great choice for the close quarters stuff, or also consider the Aimpoint PRO.

I think when I get some money I want to pickup a trijicon acog. In the mean time if I get an eotech I'm sure it'll be used on the many ar 15s I plan to build. I have a 16 inch I want a SBR and a 20 inch.

 

[colt_fan]

I bought a set of various sizes at a generic hardware store. Most likely Lowes but I don't remember for sure.

I use same files that I use to sharpen my chainsaw. They are the perfect size for the feedramps.

 

[Coyote33]

All you can really do then is clean it up with a round file and polish.

Dremel is easier than a file. ...

Any good place to take one for this type of work?

 

[chopper_man]

I'd recommend John at Remsport or possibly Scott at Pullman Arms....

 

[jtorbin88]

Any good place to take one for this type of work?

How bout in NH does acme armament do stuff like this?

 

[atilla]

Any good place to take one for this type of work?

your sofa with a beer in front of the TV?

How bout in NH does acme armament do stuff like this?

don't quote me on it, but i doubt he'd turn you away.

also, fixxah is %100 spot on in that a dremel is far easier, but if you've never done something like this before i recommend a file, don't jump right in with power tools. you can't put metal back on once you remove it.

 

[Supermoto]

So the car shoot in April I broke out the AR I built in December. It consists of a lower I built myself that functions perfectly. Now the complete upper I bought the rounds are jamming on the m4 feed ramps and sometimes even denting them pretty badly not sure what to do to fix this problem?

Do the rounds hang up when you cycle by hand? Does it lock back with one round in the mag?
Who built the upper?

 

[Terminator03]

I think when I get some money I want to pickup a trijicon acog. In the mean time if I get an eotech I'm sure it'll be used on the many ar 15s I plan to build. I have a 16 inch I want a SBR and a 20 inch.

Trust me, if I had the cash, I would be rocking an ACOG myself, but had to settle for the Eotech on a LaRue QR mount, and I also run some PA optics on other rifles, which are very good for short money btw.

 

[Mr. Brownstone]

Do the rounds hang up when you cycle by hand? Does it lock back with one round in the mag?
Who built the upper?

What does locking back with one in the mag tell you? I had that happen the other day, and didnt think too much of it.

 

[Supermoto]

What does locking back with one in the mag tell you? I had that happen the other day, and didnt think too much of it.

it shouldn't lock back if there is one in the mags. What I was saying was, If it locks back, on an empty mag, then the gun isn't short stroking.

 

[jtorbin88]

Locks back only on an empty mag.

 

[jtorbin88]

it dents the crap out of the casings,scratches the projectiles, and successfully destroyed at least 30 rounds.