AR Build. Feed issues. Sacramento help?

[Al D]

I built 2 AR15's with good components, but I'm having feed issues. The semipro that helped me assemble them thinks the Rainier feed ramp in the match barrels may be defective. So far Rainier asked for pictures of the cartridges (nose gets gouged int the feed ramp when trying to feed), but has not responded since I sent the pictures last week even after 2 emails.
Is there a gunsmith or AR 15 specialist in Sacramento that may be able to help diagnose the issue? Not looking for a freebee, just someone that may have experience dealing with assembled components.
By the way, I have tried 6 different magazines including Pmags.
Upper is a Mega monolithic. Lower is quentin defense. Standard buffer tube and weight.
Thanks,
Al

[Scuba951]

I'd post pics of the feed ramps. Maybe they're not cut all the way into the receiver like they should be.

Just a guess.

[antix2]

This from http://www.ar15barrels.com might help?:

[NewbieDave]

It could also be your lower... if it's off spec, your mag will sit wrong. Try swapping uppers to see if it happens on a different rifle. If it still does, then it's probably the upper.

Will it feed single round? Try loading your mags with 2 rounds to see if it'll load the next round without issues.

Pictures will help.


dpc

[Al D]

I sent both the barrels back. I just received the replacements. I hope to assemble them this weekend.

[Scuba951]

Will it feed single round? Try loading your mags with 2 rounds to see if it'll load the next round without issues.

I've seen overloaded mags cause issues too.
After the guy got a few rounds out the upward pressure was lessened on the magazine lips. This in turn made it easier for the BCG to strip the next round out of the mag.
However, it looked like the feed ramps weren't cut deep enough into the receiver.
I recommended he see his "armorer friend" again so he can cut some ramps into the upper.

[Al D]

Follow up.

It turned out to be the feed ramps on the barrels. Rainier was awesome about the return and even followed up on their own to make sure the new ones were working fine.

Roseville Advanced Machining who helped with my lower, was even nice enough to reassemble my upper for free just to have a happy customer.

Everything fires great on both rifles.

Thanks everyone for the input.