Hello All,
I am hoping someone can help me with feeding issue my new 9mm build is having. When chambering a round, the bullet hits the barrel just above the chamber entrance. With ASC magazines, i dents the bullet but feeds. With RRA magazines, it hits hard enough to drive the bullet back into the case. The sides of the Magazine and the sides of the feed ramp seem to line up fairly well but the bullet is still coming off at to high of an angle. Can anyone gives me things I need to check or personal experience with the same issue? Thanks

Build List
PSA Dedicated Colt lower
Spinta Precision Ramped Bolt
PSA 16" 9mm Barrel
Key mod Hand guard
Aero Precision Slick Side Upper

What ammo are you using?
Does your lower and barrel have feed ramps?
I've had similar problems with ASC mags. I don't have any issues with Metal Form.

I have tried monarch and Winchester 115 GR factory loads and 124 grain hand loads. I received a metal form mag and it feeds better but still leaves a ding in the top of the bullet.

As soon as I figure out how to post a picture in the text I will. Here are the links to Photobucket:


http://i988.photobucket.com/albums/af9/achristian8/IMG_2167_zps2fmsnpg9.jpg

http://i988.photobucket.com/albums/af9/achristian8/IMG_9645_zpsmxane45b.jpg

These links may work.

If those are RRA/Metalform mags, they look fine - maybe just the older design.  Metalform used to offer their 9mm AR mags with straight feed lips and upturned (Uzi style) feed lips.  They also offered 2 different followers - delrin and metal.  I think they only offer flat feed lips and metal followers currently (and maybe for the last few years).

I don't recall if CP/ASC did the same or if they were all just flat lip (they went through more than a few iterations on their mags).

I have almost all variations of metalform mags - blued, park'd, delrin followers, metal followers, flat feed lips, upturned feed lips - and they all run the same for me - no issues.


ETA - If those are RRA converted Uzi mags, they are also probably fine as I think all Uzi mags are that way - upturned feedlips.  I've run converted uzi mags in my builds in the past.  The only ones that I had feed issues with were ones were the mag catch was not cut at the correct location.

No arguments here, just wanted to share info.  Of the 2 photos the OP posted, the first showed a mag with orange follower (CP/ASC?) and the second showed a mag with a metal follower (I think RRA/Metalform with upturned feedlips) - I was commenting about the second photo in case there was any confusion.

In the below photo, I am not sure which mag the OP has inserted (I think RRA/Metalform), but it appears to have the older/original style upturned feedlips.  I don't have many Uzi mags left, but I found one and added it to the top of the pic to show that they came in the same upturned feedlip style.  I didn't have time to go through all my Metalform mags in storage to get a pic of the ones with the upturned feedlips and the 6 Metalforms I have out right now are all straight feedlip style.  I don't have much experience with Uzi's, but during the many years when Colt mags were $50-60 and up to $100+ per mag, I messed around with converted Uzi mags since they could be had for ~$10-15 each.  All of the IMI/MecGar Uzi mags I converted had the upturned feedlips as pictured.  I was under the impression that all Uzi mags had upturned feedlips as I don't think I ever saw an Uzi mag with straight feedlips.  But that's just my experience - I have no idea how many version of Uzi mags are out there though and which feedlip style was actually the more common one.



I believe it has been years (at least 5+) since Metalform offered their mags in multiple versions with both flat and upturned feedlips.  Based on the pic on the RRA website, it looks like they show the upturned feedlip style.


ETA - All of my builds have RRA or Spinta barrels, RRA or Spinta bolts, and Hahn or KAK blocks and they all work with Metalform or Uzi mags with flat or upturned feedlips.  If the PSA lower or barrel is too far off from Colt spec, perhaps that is why OP is having feeding issues.  I believe PSA and Brownells are only selling the flat feed lip Metalforms these days, so maybe try those and see if they work better than the RRA/Metalforms with upturned feedlips.

The Mag pictured with a black follower is RRA and the orange is ASC. I ordered a metalform mag from PSA and the issue improved. The PSA Mag sits a few hundredths of an inch higher in the magwell and have a flatter follower angle. Now there are some rounds that do not hit at all and others that have a small ding on the bullet. I called PSA and they said the buffer is 5.5 ounces with a standard carbide spring. Im thinking about ordering the heavy KAK buffer and AR10 spring to slow things down some and see if that helps.

Mad Machinist,
What can be done with the cone? After trying everything I can think of I am convinced the barrel is the issue.