AR15 feeding problem

[earthshine402]

Please excuse my AR ignorance. I am a complete noob in this domain.

I put together my first AR with a friend last year and had some pretty bad feeding problems. I'm home for the holiday and have a little free time to dork around with it. The feed ramps seemed to be cutting into the bullets as they were feeding. I used a cone dremel polishing cone to smooth out what felt like little burrs, and the rifle does now feed. However, it still seems like the issue is slightly there. If I feed a round, sometimes I can feel it hang up on the feed ramp, and also when I inspect the bullet, there is a cut almost the whole length of the bullet on its jacket.

What could be the cause of this? Mis-match in fit between the upper and lower? It is a little shaky, but from what I read, this can be normal. I have contacted CPWSA about this before I polished the feed ramp and he indicated he has never heard of this problem with his barrels.

Parts that might effect this: Spike's lower, DSA upper, CPWSA barrel. Currently feeding with PMAGs, 20/30/40, but I think it did it with some metal mags also.

 

[Mr. Brownstone]

Does the barrel have rifle extension with m4 feedramps on the receiver?

 

[earthshine402]

yes

 

[Finalygotabeltfed]

yes
View attachment 153873

Those need polishing to even them up.

 

[earthshine402]

Those need polishing to even them up.

do you mean the lips on the receiver? make them even with the barrel ramps?

 

[Finalygotabeltfed]

do you mean the lips on the receiver? make them even with the barrel ramps?

Yes. You've got an uneven transition between the two.

 

[earthshine402]

Yes. You've got an uneven transition between the two.

thanks

 

[Wrench75]

Those need polishing to even them up.

I'll second that. Thee first thing I noticed was how bad the alignment is on the left side. The right isn't so bad but the left really needs some work.

 

[earthshine402]

I just got out the dremel and whatnot, and before i started going to town on the receiver indentations, i slowly fed a few rounds. they don't even hit that area.. they start to hit the feed ramp mid-way up on the barrel side and get stuck right at the end.. i guess i can try to smooth that area out a little.

 

[mikelawtown]

are you slowly letting the BCG chamber a round? This happened on a few I had but it was only because I didn't let the BCG "SNAP" into Battery. But yea it does look like a little "LEDGE" take it down slightly

 

[earthshine402]

are you slowly letting the BCG chamber a round? This happened on a few I had but it was only because I didn't let the BCG "SNAP" into Battery. But yea it does look like a little "LEDGE" take it down slightly

when i do slowly let the BCG chamber a round, it gets hung up there on the end of the feed ramp. when i quickly cycle it or lock the BCG back and let it go with the button, it feeds fine, but when I eject the round and inspect the jacket, there are scratches on the bullet. I gave it another round of sanding and dremel polishing to no avail. I might just have this rifle be a blaster rifle, and then maybe look for a complete one that was put together by one company.

 

[mikelawtown]

when i do slowly let the BCG chamber a round, it gets hung up there on the end of the feed ramp. when i quickly cycle it or lock the BCG back and let it go with the button, it feeds fine, but when I eject the round and inspect the jacket, there are scratches on the bullet. I gave it another round of sanding and dremel polishing to no avail. I might just have this rifle be a blaster rifle, and then maybe look for a complete one that was put together by one company.

if I slowly do it it also catches but its new (complete upper from one company) so I don't think its uncommon if feeding slowly. at the range it shoots without issues.

 

[headednorth]

I cant say Ive ever examined a bullet for scratches after its been chambered. Maybe its normal to some extent.

I think having feeding issues while slowly feeding a round or feeling it hang up while hand feeding is to be expected. I was always taught when loading any semi auto to rack the slide/charging handle fully to the rear and let it fly forward under its own pressure, or hit the slide release if the bolt/slide is locked to the rear. Either way, the slide/bolt is quickly thrown forward with a good amount of force, as it was designed to operate. "Riding" the slide/handle slowly forward can cause feeding issues. Just my two cents.

 

[earthshine402]

I guess i wonder how much it affects accuracy, only way to find out is to test it at the range

 

[Mr. Brownstone]

When taking a class at Sig, a guy had a brand new Stag that was shooting wild every other round. The instructor noticed that there was a burr in one of the feed ramps, so every bulet that fed from that side was getting scratched and flying wild.

 

[SIGPRO 226]

are you slowly letting the BCG chamber a round? This happened on a few I had but it was only because I didn't let the BCG "SNAP" into Battery. But yea it does look like a little "LEDGE" take it down slightly

This.

 

[StevieP]

Never 'ride' the charging handle.

Let it fly. Every time.