TM VSR-10 Upgrade Clairification

[WarSAW]

I am looking into a TM VSR-10 G-Spec, and I came accross the following upgrade guide:

www.airsoftretreat.com/forums/index.php?topic=2881.0

I would like to buy a VSR10 and upgrade it with the ps150 spring, in order to stay within MIA FPS regulations, as I am afraid a stronger spring will push me beyond 550 fps.

My question concerns this section:

"Laylax pss10 ps150 spring: 492 fps*
Needed:
-Spring*$18
-Trigger sear*$35
-Piston sear*$21
-High pressure piston*$45
-Spring guide*$25
-Spring guide stopper*$21
Recomended:
-Silent damper piston head*$19
-[glow=red,2,300]Zero trigger(replaces the whole trigger assembly and piston.You will not need any of the parts stated above if you purchase this)*$185"[/glow]

Is this guide correct in saying that if you purchase the Zero Trigger that comes with the cylinder, such as the one here:
www.hotspotairsoft.com/hsastore/product_info.php/cPath/23_63/products_id/474
that you only need to buy the spring, and not any of the other upgrades listed?

[kdogg]

The zero trigger comes with the piston, not the cylinder.

The Zero Trigger would be the better way to go if you ask me personally.

All you need is the fallowing:

The base gun (VSR-10 G-Spec)
Zero Trigger set
Laylax spring
Laylax spring guide
Laylax cylinder.

You can technically get away without getting the cylinder though.