When you say - lock the moment you pull the trigger more than twice....
Is the gun stalling, struggling to cycle etc....
(which it shouldn't be with a 16tpa neodym motor so much)
Or the trigger is like on safe mode - refusing to travel properly coz COL is raised
(or the odd v3 safety arm on other side is impeding the silver two part trigger swinging upwards and pushing trolley)
In other words real resistance from COL not resetting or settling so trolley passes over COL arm (so COL lifts to pop trolley later)
Or trolley is jumping off of trigger mechanism - through worn components, at full pull
which is not really "locked" as I would call it
Now you say you replaced the piston with a SHS one ???
A Blue SHS steel rack piston ???
Coz they can, well do bind in the JG V3 I just tested - use a Cyma piston or check binding
sand/file the piston/runners & retest to ensure piston doesn't bind
Now if the piston binds, it will slow and release late, it "might" slow that sector rotating at last few teeth,
that might make the drivechain near stall on release briefly and leave the sector in a later position with COL still raised ???
That COL slightly raised would lock the trigger in dead zone maybe
So need to clarify what you mean by "locked" specifically
Also was this problem happening prior to these "upgrades"
and/or what other parts/upgrades were performed by previous owners
did it have an ongoing issue before you bought it - or got worse since you upgraded it
JG box I tested with 2 SHS pistons, that were binding in my v3...
Check piston for binding by inserting in box, tilt box up/down and piston should rise/fall freely
my guess is that if your SHS is like my "regular" SHS Blue steel - it will probably bind
Between the grooves/channels, that moves on the gearbox piston rails inside
JG stock piston measures 18.26mm
Cyma metal rack measures 18.29mm (doesn't bind)
SHS measures 19.2mm & does bind, not moving freely
Unsure about the lightened SHS pistons with holes or slots in
my two were regular & another I started to swiss a while ago
But SHS pistons can bind in a fair few boxes, and a little tight at back of box in a few more
& binding pistons can cause some weird issues & rob you of rps (even fps) & efficiency & add wear too
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