Weird gradual fps drop issue (aeg)
 

Hey everyone,

I have another interesting one. I just finished modifying an umerex g36c and now that it's assembled, it's shooting but it will shoot 379, then 354, 316, 275, 110, and keeps bouncing all over.

I am pretty confident the gearbox is working very well. I have rebuilt g36s a thousand times and with any gearbox, I can hear that it's running smoothly and airflow seems consistent.

The problem lies within the barrrl. When fps drops I can hear a weird muting sound on those shots and the ones that shoot at the proper speed have a much nicer pop sound to them.

I am about to rebuild the barrel and change up the bucking but if anyone has any ideas, please let me know. If this barrel rebuild doesn't do the trick the. I will post a video because I have never come across this and I have done A LOT of gun work over the years.

Thanks,

could be a feeding issue, or a hop rubber with a sealing lip thats too tight
The muffled sound most likely indicates a jam, and the air pressure needs to build up to fire the BB past it.
Try taking the barrel group out and pushing a BB through the hop rubbers seal lip by hand. Should take much more than the weight of a pen to push it through.

It must have had something to do with the hop rubber. I have used this bucking with this exact build before but for some reason this one just didn't like it. I swapped it out for a thinner one and it seems to be working as it should!

Thanks!

Problem solved!