Alright, first time at the range, and this gun is tight, so I wasn't terribly suprised when it had some very minor issues.  

Bulgy kit on a 1.6mm nodak spud receiver.

I fired around 500 rounds through it, using ammo and mags that worked perfectly in my Krebs.

Bakelite 30's and 45's.  Russian surplus from RGUNs.  

There were 3-4 FTF's where the round would make it part way up the "feed ramp" if you can call it that, but those happened early and seemed to disappear.

The other issue that I'm more worried about is the fact that the gun would at random (no more than once per magazine, and typically every other magazine) fail to strip a round from the magazine.

The mag sits high enough, and there really isnt enough slop in the bolt to cause it to ride over the round, atleast thats why my half-assed "trouble shooting" told me.  

A buddy of mine was there, and we both came to the conclusion that it must be short stroking.  The problem happened with ammo/mags that have been run in other AK's with NO issues, and it appeared as if the magazine height was perfect relative to the bolt.  Feeding by hand showed that there was plenty of bolt/round contact to strip one off of the magazine.

So from then, we figured it must be short stroking.  We swapped out recoil springs, and could not recreate the problem from then on.

We oiled up the recoil spring that came with my RPK, and then after that we couldnt recreate the problem.  It seemed to cycle by hand smoother, though I fail to see how the recoil spring setup in an AK could "bind" to the point where it would short stroke.

The RPK throws spent casings like a madman.  20-30 feet with ease, from one end of the firing line to the next, yet it was still "missing" rounds.  Its very frustrating to hear an AK go "click", then pull the bolt back only to see there is no round in the chamber.  I know strenght of extraction is a key way to tell of an AR is short-stroking, but I have no idea if the same holds true for an AK.

Any other diagnosis methods that I can use to figure out WTF is going on?

Is it possibly just new gun teething issues?  The RPK had a flawless finish, right down to the bolt...the guts of the receiver, the carrier...is it possible that the combination of being new/tight with no "wear" is what caused this?

Am I missing something obvious?  Most important...should I be worried enough to send it back?  Like I said before, I could not for the life of me recreate the malf at will.  It was totally at random, and seemed to occur less as more rounds went through, but then again it also happened once when I got to the point where it seemed everything had worked itself out...

Also...there was no detent in the receiver to keep the safety down, and it kept walking upward.  Very annoying...but it never moved up far enough to engage the safety...only about half way.  Any possible issues there?

Thanks guys,
Scott

I had some issues with mag springs once that were like what your describing.....You may have a worn mag spring that is fail ing to present the round to the bolt face fast enough to get stripped from the mag.

 It gave me fits for awhile but when I swapped the mag springs out with some of the wolff brand +5% power springs it dissappeared. Mine was acting like yours except sometimes you'd find a drag mark on the cartridge case making it look like a short stroke or it would stovepipe and dent the case...Could be a combo. of a new recoil spring and old mag spring IMHO.

The selector stop may be cuasing this. Sounds crazy, but follow me on this one. The mag catch may lock tight giving little forwards/backwards play in the mag, but the thickness of where the top of the mag lug contacts the selector stop plate is too thick, thus not allowing the mag to position correctly. I spoke with Vector for about 30 minutes on this topic, they milled material of off of the selector stop plates but some may have been missed.

In my opinion you should ALWAYS call the manufactuer before asking arfcom for help.

Quoted: The selector stop may be cuasing this. Sounds crazy, but follow me on this one. The mag catch may lock tight giving little forwards/backwards play in the mag, but the thickness of where the top of the mag lug contacts the selector stop plate is too thick, thus not allowing the mag to position correctly. I spoke with Vector for about 30 minutes on this topic, they milled material of off of the selector stop plates but some may have been missed. In my opinion you should ALWAYS call the manufactuer before asking arfcom for help.

Can you provide a photograph explaining WTF you just said

Thanks guys,
Scott

ETA: Called them, getting a return label lol.

If you need money to fix your Vector, you can sale me that wonderful 5.45 KTR.

Quoted: Quoted: The selector stop may be cuasing this. Sounds crazy, but follow me on this one. The mag catch may lock tight giving little forwards/backwards play in the mag, but the thickness of where the top of the mag lug contacts the selector stop plate is too thick, thus not allowing the mag to position correctly. I spoke with Vector for about 30 minutes on this topic, they milled material of off of the selector stop plates but some may have been missed. In my opinion you should ALWAYS call the manufactuer before asking arfcom for help. Can you provide a photograph explaining WTF you just said Thanks guys, Scott ETA: Called them, getting a return label lol.

Every receiver has different measurements between the top rail and bottom of the receiver due to manufacturing sloppiness. Since the carrier rides on the top rail, this distance affects the bolt's relationship to the rounds in the magazine. The commies would ensure a consistent mag height by milling the selector stop to each individual rifle as needed. When you throw a kit together with a selector stop fitted to another receiver, then problems like this can surface.