pulling out what little hair I have left.

Just received  two new 15 round mags from auto ordnance to accompany my 10 round mags from another mfg. I also have a 20  (?30) mag that came with my plainfield carbine. It has been gone through fully including new extractor ejector, springs etc. I get a real high number of failure to feed, failure to extract. and now the new mags previously unused. are almost impossible to place and lock in the action.. This occurs with remington , winchester, and Aquila factory loads and my reloads too. What could I have missed in all of this? All I want is a rifle that cycles reliably. Please, any and all suggestions welcome. 

Are all these commercial type magazines? Some commercials are known to be problematic. There can also be slight tolerance differences between commercial housings and GI housings. Make sure you have a good GI mag or one of the recent Korean mags., which are known to be reliable. 

Edited by floydthecat - Aug 22 2019 at 5:53am

By the way.... you are not an oldfart yet. When you reach my age, you may be an oldfart😁.

W5USMC wrote: Is this the same Plainfield carbine that has the "hump" in the middle of the feed ramp?

it is, but I have compared it to others at my range and the hump is present in all of them,  thanks!

oldfart69 wrote: it is, but I have compared it to others at my range and the hump is present in all of them,  thanks!

Maybe the same gun smith in your area is screwing up more than one carbine.

Here's the thing, of my 13 carbines (granted all usgi) none have a "hump" like that in the center of the feed ramp. Below is a picture of your feed ramp as well as another Plainfield feed ramp taken from the Plainfield section off of the main site for comparison. My thought is, in order to get a ridge "hump" in the center as predominate as there is on your feed ramp, then there has been considerable polishing (grinding) away of original metal. Possibly resulting in way too much of the original ramp removed, what is left of your feed ramp is no longer guiding the bullet into the chamber like it should.

Charlie, I do see what your talking about and it sure looks like dents in the picture, oldfart will have to confirm whether it actually is dinged up.

Olefart69,

painter777 wrote: Olefart69, Can you manually cycled rounds in and out of it without interruption? I've seen heavily used M2 receivers where the feed ramp has developed a groove on either side something like this- .......... /\........ but don't ever recall a ridge like seen on yours. I don't know if there is enough of a ramp left on yours to allow for more polishing to correct a feed problem. But before scrapping a receiver I'd have to attempt it. Only after everything else has been checked out and ruled good to go. Polished/grinding as a last resort kind of thing. is the feed ramp part of the receiver or barrel? Just trying to learn here. if this goes on so it bothers the admins just let me know, thanks

oldfart69 wrote: is the feed ramp part of the receiver or barrel? Just trying to learn here.

The feed ramp is part of the receiver. One thing, I know that you have mentioned trying a number of different magazines but I do not recall if any have been USGI mags, as mentioned by other members USGI magazines are the way to go. I personally think that your receiver's over ground feed ramp is the problem but USGI mags are not very expensive and may be worth a try.