So I recently traded a few guns for a Vector MP5/40. Serial number is under 120, not sure if that is considered "low" or "high" for this gun. No SW markings on it. Finish seems to be a shiny paint-like substance that seems to chip off of the gun. Unsure of who built it.
Current issues are:
1. FTF - Probably the magazine, as it's a crappy aftermarket black one with an apparent cracked feed lip. I already have 4 brand-new HK MP5/40 magazines for it, which fit in the magwell fine, and feed great, BUT this brings me to the second issue.
2. The HK factory magazines will not lock into the gun. It almost seems like the magazine well is either too long, or the magazine catch is too tall, both, or maybe the factory magazines are out of spec, which I doubt.
3. Sporadic FTE hand cycling. When it DOES feed fine, the bolt doesn't always let go of the cartridge, but if I cycle it enough it eventually tosses the cartridge 8 feet away from the gun.
What I have already done:
1. Swapped the recoil spring for a factory HK MP5/40 spring I got from HKP.
2. Ordered (but not received yet) a factory HK MP5/40 ejector, ejector spring, extractor spring.
3. My original plan was to remove the paddle mag release and carefully shave off material until the factory magazines would work.....until I realized that it's apparently welded into the gun. Derp.
This is my first MP5 clone, so I'm genuinely at a loss of what to do. Not a whole lot of information on the internets concerning the Vector MP5/40 troubleshooting that I could find. Any tips would be appreciated.