[ichimaru gin]

Guys, I upgraded my hi capa with shooters design metal slide and frame. With some advice from the gurus in this forum(Sir illusion, Sir Daiviet and Sir Tyson), I did some filing and sanding to make the slide action smooth and optimal.
These are the parts that I smoothen out

rails
base of blowback housing
frame wall where the back of the magazine touching
Outer barrel
spring guide

I also put enough silicon oil on the rails. Racking the gun was no problem and it was smooth.

I think I did the best I could to optimize this gun's action and I still find it gas munching. I can only shoot 21 Bbs with hi cap 4.3 mag. 25 bbs with hi cap 5.1 mag.

I was thinking maybe the mag valve is not aligning properly with the square hole on the nozzle( I dont know what its called, is it the "gas chamber"?). So I did this test : I removed the silicone oil layer on the square hole, Put silicone oil on the mag valve and install the magazine. And then I removed the magazine, and I found out there is a layer of silicone oil on the square hole. that means, the mag valve was in contact with the hole, right?

Can you guys tell me any other cause that would cause high gas usage?
Would replacing the standard marui blowback unit with shooters design one fix the problem?

Thanks in advance