Ya, VSR is really rough on sears when upgraded, even aftermarket sears break with moderate springs. So Zero Trigger will be required (and the associated piston), a Laylax/First Factory PSS10 130 spring (sit around 430fps), and tightbore and bearing spring guide would add around 25fps. And make sure you cut off the airbreak (the ***** that sticks out the front of the pistonhead), otherwise your velocity will sit around 330-350fps regardless of what spring you put in.

Hello everybody I'm new to this forum I just bought a classic Army m24 LTR just wondering if I can upgrade the piston spring and spring guide With VSR 10 compatible parts