Did a test with my aeg in inverted position. By gravity, the bb doesnt go all the way through the hopup bucking. Looks like the nozzle is a bit long. I would have to help the bb to push through before it goes to the chamber Filing it by few mm would give me an air-tight issue..

Now i'm no where to go.. last thing to do is to buy another magazine to test it. But the one i have right now is perfectly fine.. it could spray 20-25 bb if i intentionally free the lock.

that doesn't mean the spring is strong enough to feed.
My ptw mags, for example, spray about 120 round up to 10 feet, but they don't feed fast enough for my ptw.

if the nozzle is too long, the BB's won't feed up into the chamber. Make sure it's an M4 nozzle you have and it's compatible with your specific brand. I did some testing years ago and changing the length by .25mm is enough on some guns to prevent feeding, or cause a serious air leak.

try reinstalling the hop rubber and see what happens. Lube the OUTSIDE of the hop rubber to help it slide in the hop chamber.

Thanks. I've already tried re-installing the hop up rubber countless times and get same results.

I want to know if it's normal if I feed the BB in the hopup chamber by gravity, it doesn't really fall through?

it should require slight pressure to push it through, like the weight of a 4" screwdriver.
If you actually have to push down and pop it through, the lips are too tight. I recommend a new hop rubber, or use a rolled up piece of sandpaper to open it up a bit.

Did you mean going inside the barrel? What I meant was the BB is not falling through the hopup chamber when the gun is in upside down position (no magazine, just manual feeding). I have to push it a bit just to get inside the hopup chamber where it meets the nozzle. It looks like somewhere is jamming before it reaches the hopup changer.

Anyhow.. how can you tell if you have bad magazines?

My magazines are about 9 years old.. But by the looks of it, it is still working fine. I also have a delayer chip in my sector gear.

bad magazines don't cause that problem. when the gun is upside down BBs should drop into the hop up with no pressure. Just something there to prevent them from bouncing out.

Was the nozzle ever changed?

could be the nozzle isnt all the way back as well?

can the tappet fin wear at all from previous use?.. maybe the issue is just manifesting now that you've pulled it out of the closet to shoot.

If the nozzle wasn't changed that's the only other thing that affects the stroke of the nozzle to not be pulled back far enough.

I've already replaced the nozzle and the tappet plate. I suspect that it is somewhere in the magazine to the hopup chamber is the issue...

I did another tests:
My AEG is a tm aug.. i pulled out the barrel from the receiver and fit my gearbox to the hopup bucking Each time i drop a bb, it would drop flawlessly. (Like it should) no binding with the hopup nor with the nozzle.

Now.. without the front receiver and the barrel.. i test fit my magazine to the receiver. A lot of bbs shoots up.

But when i put everything on.... i get dry fire. Feels like the magazine, or the magwell.. are not aligned together with the hopup bucking.

This is just my theory.. im not sure if anyone have experience the same thing.

did you measure your old nozzle vs the new one?

I found the problem. I dont know what happened through time but the bb well (or the hopup bucking) is off by about 2mm.. i can put a washer on the hopup bucking to offset the mis alignment.. but that would mean the nozzle would sit 2mm farther from the hopup. I can fix the feeding issue but i would sacrifice the air tightness.

If you ask me why i cant do it in the bb well instead.. i have tried that. The magazine will just push it off when inserted.

I'm not sure if you can picture what im talking about.. i'll try to post pictures soon.