Figured I'd post something I did today while watching the Olympics. How can I cheer for USA without an M4 in my hand?! I did not get any pictures of any of the parts in little baggies before I assembled it, maybe if I end up buying one myself I could do a video of it being built. I built this for someone back in Rochester. Cost of the kit was $250 after Evike's coupon codes.
Overview of the gun. The nice thing is it comes with one of the legendary G&P PMAGs. The mag is made of aluminum, and has an extremely tight fit in the magwell.
Dark shot of the right side. It looks like there is a legitimate serial number from PTS. It is the only thing not roll marked/engraved onto the receiver. The bolt is a VN cut out style (has some areas cut out in the rear section) with forward assist grooves. I don't think the forward assist works though, I tried a number of times to push the bolt with no avail.
(I know the last one is probably blurry, but you can see the Magpul logo on the side)
Looks like a Gen 1 MBUS rear sight, with a PRI style charging handle. It is very comfortable to use with one hand, even if wouldn't have come with the extended latch.
Even though the externals are pretty good. The internals are meh. The challenge kits are based on the WOC-X I believe(or WOK as it is labeled on the box), which has aluminum alloy internals, with a steel auto sear and a steel insert on the bolt release. These should last just fine, but at some point they will be needed to be swapped with steel.
Picture of the buffer. I don't know why there is a little silver ring on it, but it makes the gun harder to field strip. This is probably due to the number of older WOC kits that had receiver wobble problems.
The gun is not without its problems though. The nozzle assembly is a b$*@# to assembly with the pins. The WE M4's are 10x easier to do IMHO. I don't know if it was just my kit, but the bolt carrier was very stiff in the upper. I have to cycle it a number of times to loosen it up. Like I said earlier, the mag is very tight in the magwell, and was sitting too high causing the carrier to not cycle all the way forward. I shaved the magazine release a bit and it seems to have helped, but I need to keep at it to completely solve the problem. The auto sear does not contact the hammer enough, so I will either have to bend it back to engage or buy a new one. I hate the hop up unit's little tiny spring that for some reason is 10x more powerful than most people could imagine. I almost lost it when it flew into my face. Luckily I had a motor on hand and picked it up off my floor. The bolt feels sluggish too, so it might need a stiffer buffer spring. It works fine right now, but it still needs some tweaking.