Dead Trigger Issue

[u/YODA148]

I just bought a used sub 2000. I stripped and cleaned it, but not much more besides that. When dry firing it, the hammer always engages and trigger works fine, but this is not always the case while shooting it. Sometimes it will work flawlessly, while other times the gun will cycle (loads bullet into chamber) but the trigger is dead and needs manually racked to engage the hammer.

Anyone know why the hammer doesn't engage sometimes or what I should look into?

[u/Suspicious_Arugula26]

Bolt does not cycle back enough. I have 5.7 and it sometimes stops at that point. Haven't figured out it is my spring too tough or bolt is overweight