Looks like there may be some bad stamping going on with the current crop of "P" guns that are coming in from Century.
ETA: I think it's clear this isn't a one-off, is most likely widespread. What's not clear is what other areas of the receiver may not be stamped correctly and what internal, mechanical negative effects this might cause long-term.
With the bolt locked open and an empty MKE mag seated in the magwell, riding the charging handle closed (no HK slap), the bottom of the bolt hangs up on the magazine feed lips. It's enough to make the bolt stick open unless it's forced closed. Just running the bolt a few times over the empty MKE mag has caused the bolt to rub the finish off of the top edge of the feed lips. Doing the same thing with an HK mag exhibits no hanging up and no finish wear on the feed lips.
While there is an obvious difference in tolerance and/or height at which each mag sits on the catch/in the magwell, the issue might actually be more indictive of either an out of spec catch, receiver, or both. When inserting a mag, there is a bit of upwards play with the catch. After the mag is fully seated, the catch comes back to rest at the bottom of the hole in the receiver.
Based on others' reports, swapping out the catch with an HK one seems to be a good first step in correcting the mag catch issue. Now if I could only find one in stock...
Picked up an AP5-P Navy from my LGS last week as well as a few mags from Deutschland. It's my understanding that the Turkish-made MKE mags are mfr'd using older tooling that predates refinements HK has made to the design in recent years which may explain, at least partially, why the German mags are considered to be superior, especially with heavy flat nose and hollow point projectiles.
The feed lips are clearly different (emphasized). Another thing I noticed is the welds on the HK are perfectly uniform, whereas the MKE welds, while not terrible, are rough by comparison. It is clear that the Germans know how to dial in a robot welder. Lastly, there is a feeling of smoothness that the HK has when pushing down the follower with my finger. The MKE feels extremely gritty which may or may not be partly or entirely caused by the rough welds. I think a combination of old, worn out stamping dies and rougher finishing/finishes is also to blame.
I've yet to put any rounds downrange with either mag, so take all this for what it's worth.
Besides the ejector, extractor, and extractor spring, is there anything else worth replacing with genuine HK parts to bring the MKE closer to its German cousin in terms of reliability?