Maintenance:
Now before i get into what i do, id like to point out that how i do it and what i use are not the only way of doing things. People use all sorts of different oils, grease and sprays to get the job done. As long as it's suitable for the job, all is well.
Items:
Wurth High performance dry chain lube (Teflon/ptfe spray)
Wurth brake and chain cleaner
Airsoft Engenuity cleaning rod
Silicone oil
paper towels
Step 1:
Remove the magazine and split the upper and lower by popping out the body pins. From there, remove the charging handle and bolt carrier group.
Using the paper towel, wipe them down properly, including the channel on the underside of the charging handle. This is what mine looks like after one game day and a bit of testing.
Step 2:
With the moving parts cleaned, we need to move onto the upper receiver. There is no point cleaning the moving parts if the walls they're sliding against are still dirty, so wipe down the inner walls of the upper receiver as well as the grove that the charging handle runs in.
Step 3:
We're going to finish off the cleaning of the upper by cleaning the barrel. I use an Airsoft Engenuity Optirod because it holds cue tips at a slight angle instead of cutting little strips of tissue, but any will work just fine.
I go in from the muzzle end and stop before the hop up so i don't disturb it or damage it in any way. Because i use propane, i don't get silicone oil or other crap all over the hop rubber. If you do, take a cue tip and gently push it inside and twist. you don't want to apply any sort of pressure because you're at risk of rotating the rubber ever so slightly or damaging it.
Step 4:
Moving on to the lower.. I have two processes that i do to the lower. One after every game, and one after every 5. The only difference is on the 5th clean i spray out the lower with brake/chain/carb cleaner. Because of how tight everything is packed in to the MWS trigger box its hard to completely clean it without removing it from the lower. with carb cleaner it will blast out all of the deposits and degrease the trigger mech completely. what will happen is the spray will run into the gaps and drip out of the trigger hole in the bottom of the lower. The spray evaporates in the air, so after about 30 seconds it will be bone dry, leaving behind a clear trigger box. For the daily clean, i just wipe down all visible surfaces with a cloth/ paper towel. In order to keep a reliable bolt lock, push the bolt release and clean the faces of the ZET plate when it lifts up. if you get crap between there, it can slow and not lock back reliably. Especially running green gas, which cycles the gun faster.
Step 5:
Everything is now clean, so we can start with the lube. There's lots of options out there but one thing that's important is this... SILICONE OIL IS NOT FOR METAL ON METAL PARTS. over time, silicone oil will make metal bind and is the exact opposite of what we want to do. Silicone oil is important, but only for sealing components. I use Wurth dry chain spray for 2 reasons. If it can lubricate and stand up to the temperatures of chain/sprocket contact on a 200mph motorbike, it will do just fine on our bolt moving 8" forward and back. The other reason is it isn't messy. it dries in the air and leaves a light film on the surface so it isn't going to get thrown around the inside of the gun. so give it a good spray and give it a few seconds to dry.
Step 6:
Back to the lower.. If you're using a spray like me, put your finger over the hop up entrance in the lower receiver and give the inside a quick spray with the lube. YOU DO NOT WANT ANY LUBE OR ANYTHING ELSE ON THE HOP RUBBER. If you're using a grease or oil, this is less of an issue (until you fire the gun and it throws it all in there anyway)
Step 7:
Spray your BCG and charging handle with lube. Pretty self explanatory so i didn't bother with a picture. What i do is hold the bolt by the nozzle with my thumb covering the underside of the nozzle. this stops any lube going into the nozzle chamber.
Step 8:
Last thing to do is lubricate the sealing parts with silicone oil. This step is only really needed if you use propane, as green gas should keep the sealing cup on the nozzle adequately lubed and i do this every 5 games. Pull the nozzle out and place a couple of drops of silicone oil between the nozzle and the BCG. On WE guns you can pull the nozzle out far enough to apple lube directly to the o ring, but you cant on an MWS without removing the nozzle, so this is as good as you can get. Like i said though, if you're using green gas, this shouldn't need to be done often.
Step 9:
Put it all back together because you're done!