[Caelum]

1. The stock collapsing is a common issue. You will need to either modify the stock catch with a dremel or hand file, or order a replacement from WE, or a european retailer. Both would methods require a field strip+ some further disassembly.

2. I don't know for certain what could be causing this. Check to see if it occurs with each magazine. If it only happens with a specific magazine, then it is probably a worn out magazine follower. If it happens with each magazine, then either the bolt catch system, charging handle, or every magazine follower is worn down. To find out, you will need to do a field strip to inspect the charging handle, or a more detailed strip to look at the bolt catch assembly.

3. Make sure you are filling the mag up fully. Fill it upside down, and for about 10 seconds, then let the magazines warm up before you try to shoot the gun.
Look at the facebook link I posted earlier to ID what generation mag you have. The rubber seal at the top of the magazine could be different, 1st gen mags don't seal against the nozzle as well.

4. Buy some high quality bbs. Test the followers without any bbs in the mag to see if there are any areas that catch. Sometimes magazines just need to be cleaned or broken in.


5. Again, buy some high quality bbs.
The hop up is an area that you need to be careful with. If you torque the hop up adjustment bolt too much, you may break the tension arm. You mentioned that the gun was really greasy, so it could be that the hop up rubber is coated in oil+ isn't able to apply hop correctly. This could cause your fps/accuracy problems. A more detailed strip down to get to the hop up rubber would be required. Once you got to the hop up unit, you could try soaking the hopup rubber in warm dish soap+ water then drying fully to see if it helps. If the rubber is covered in grease, then you would probably want to fill+ empty the mags a few times to get rid of some of the silicon oil that is trapped in the mags/ nozzle.

6. What do you mean by "It won't go full auto"? There could be various things causing this, so clear pictures/video would help us help you.
When you cock the gun, set the gun to full auto, then pull the trigger, do you hear a click? Does the gun shoot well on semi auto?
Try looking at the loading nozzle for breaks or cracks too, you shouldn't need to take it apart to look at it, but a field strip would make it easier.

If you want to fix this, you will need to take it apart. That's just the way buying cheap used guns goes. If you are handy, you could probably figure it out. If you don't think you can do it, then see if the seller will take returns.

As far as guns to learn to tech on, the smg8 isn't a great choice. Replacement parts are almost non-existent, there are not very many guides or tutorials, and the gun itself has a few inherent problems. If you need replacement parts, WE is really the only source for every single part, and they have a significant wait time.

If you decide to keep it + see if you can fix it, watch all the youtube videos you can (regardless of language), and get familiar with the parts diagrams BEFORE you take anything apart. The diagrams are available on the WE website. Field stripping the gun isn't hard or complex, and even removing the internal frame isn't that difficult (there are a few pins to remove, and about 4 springs that you need to be aware of), but you need to go slow+ keep track of everything.

Please realize that we can't walk you through every single step, you have to be competent enough to know how to find the answers for yourself. The information is out there, you just need to take time to google and read through old threads.