Hi all,
Have an LDX advanced in my blaster. It was running fine, no problems. Decided to change it up and switched out the 7" handguard for a 10". At the same time I put in a new longer barrel, new outer barrel and put in a cylinder that wasn’t ported as much… at about 1.68 on the air volume level, from memory.
After changing those components im getting lower FPS, some as low as in the 100s. Max of 270, average around 260. Before component change it was 300-310. Also having feeding issues. Every 10th shot or so it dry fires.
Would appreciate any advice.
Cheers 
Is t peice clear? No glue spilling into it?
it was the same before i glued it in
Low FPS, feeding issues etc. is most likely nozzle/t-piece sealing or tappet plate issues.
Some detailed pics are pure golden to be able to see if there’s anything that sticks out as an issue.
Basically just open up the box.
Check/test cylinder and cylinder head/nozzle sealing on the gearbox.
With the gearbox split, rotate everything and make sure tappet is opening/closing full travel.
Dummy fit/push the t-piece, barrel and handguard setup onto the front of the receiver/gearbox and make sure that nozzle is fully seating within the t-piece.
I used to check and set with around 1-1.5mm preload for my t-piece to nozzle seals…. any nozzles/tappet distances that weren’t long enough to achieve this preload, I would either modify the tappet where room allowed, or failing that, made my own extended nozzle rubbers to get the right results 
From your issues and the only changes that you have done to your blaster…… it can only be air seals/nozzle travel/seating that could be the problem.
When changing the outer barrel, did you change the barrel adaptor?
It almost seems like the tpiece may not pressed back to the gearbox correctly. Some adaptor and tpiece combinations, require a longer tpiece spring.
Just changing inner barrel and cylinder should have no change in sealing and feeding, so are there any other variables when you did the change over?
Did you re-use the original t piece? Was the new IB free in the outer? I’ve got a black barrel in one of mine that’s definitely bigger than 9.5mm, always a bit too snug in a CYMA outer barrel, doesn’t allow the t piece spring to do it’s thing and seat the t piece properly.
My mate’s did the same thing after a barrel swap… he’d forgotten to refit the t piece spring onto the barrel during reassembly. 