My MP7 has been running quite nicely… but I figured I could try to get more out of it. Last time I serviced it, I threw the following parts into mine: FE Steel Lengthen Piston, Wii-Tech Rubber Stock Pad, and the Wii-Tech Selector Pin. The piston and stock pad are just upgrades that I wanted to do anyway (harder kick and more realistic butt pad), whereas the selector pin was purchased to repair my worn out OEM part.
Read on after the break for photos of each product, a description of what it is and what it does, as well as a comparison photo between the OEM part and the aftermarket one.
FE CNC Steel Lengthen Piston
Replaces KSC/KWA MP7A1 piston. Re-uses standard KSC/KWA piston cup.
Extra weight = extra felt recoil. I haven’t owned or handled or shot the RA-Tech MP7 hard-kick set, so I can’t compare to this… but I imagine that its somewhat similar.
The lengthened piston likely works somewhat like how the PDI “Winter” piston heads work; but I’m honestly still not entirely sure what exactly they do since I haven’t really fiddled around with those all that much. To be frank though, if it works, I don’t really care. And it still works.
Wii-Tech Rubber Stock Pad
Drop-in upgrade rubber stock pad to replace the hard plastic stock pad on KSC/KWA MP7A1. (Pictured: Wii-Tech pad on the left, factory stock pad on the right.)
Rubber feels better – it actually grips whatever your stock is resting against. I suppose I could have just rubber-dipped the existing butt pad, but this was cheap enough that I figured I would order one just because.
Surprise feature – holes in the bottom of the stock pad actually accommodate the take-down pins from the Umarex and KSC MP7 (I’ve verified both, though the pins are exactly the same irregardless).
Wii-Tech Selector Pin
Drop-in machined pin to replace the original factory selector pin which can wear out.
My Umarex MP7’s selector no longer clicked after a couple weeks of purchasing it second hand – I suppose this is just normal wear and tear that occurs when the cast pot metal OEM selector pin wears out from contact with the ring that interfaces with the selector when it rotates. The aftermarket pin alone has not entirely fixed my mushy selector, I suspect that the collar will need replacement as well – though I do have access to a parts gun KSC MP7 that should have the necessary replacement part in better condition than mine. To be honest though, it works as it should now, just the click is just a little weaker than most other MP7’s; I can live with this as is.
At the very least, this pin allows me to actually shoot long bursts of full auto, without having to hold the selector in the correct position to get more than a few shots out at a time (as I had to do previously). Before installation of this new pin, bursts of full auto would usually end abruptly with my finger still holding down the trigger – setting the selector to semi would allow me to continue firing, as would cycling the selector out of full-auto and back again… holding the selector down in the full-auto position with my thumb over it also allowed consistent fully automatic fire.