Double Feeding with midcaps - Possible solution

[solid1191]

I recently bought a new classic army mp5a3.

When I tried it out with the highcap it worked quite well, without feeding problems. I tried two CYMA midcap magazines and to my disappointment it caused feeding problems. It would double feed.

I read online about changing the bucking to fix this, but because I am quite new and the gun is brand new, it seemed too invasive and I didn't want to break the gun taking it apart.

I turned the gun upside down to inspect the feeding nozzle. I put a bb into the nozzle, I followed up with another bb. I gave it a little pressure with a tooth pick and observed two BBs get pushed into the chamber.

I suspect that the midcap is feeding with too much force, causing two BBs to be lodged in front of the nozzle.

I decided to trim the springs in the midcaps and I am happy to report that it improved my feeding substantially. With a magazine of 60 rounds loaded, it only double feeds once or twice.

Here are the steps I followed, in case someone else has a similar problem.

1. I took out the pin at the top of the midcap to remove magazine from the metal sleeve.

2. I located a small door with a screw on the magazine where the spring is housed.

3. I unscrewed the screw on the door and the spring popped out. On one end is a plastic nub that pushes the feed lip. The other end is a plastic piece also acts as the door as mentioned above.

4. I trimmed the spring gradually, I think I have taken off three inches or so.

5. Re-assembled the magazine.

6. Test fire, good results but not perfect.


I read somewhere that changing the small spring located near the feed lip will help as well. Can anyone comment on how this would stop double feeding? Would I be putting a stronger spring in there?

Hope this helps!