Spring stuck in piston

[LT Teach]

So I was teching a VFC PDW that wasnt responding and I found this inside. Have you ever encounter something like this? I was kind of worried manipulating this piston lol. My guess is that the spring got bunched up and the ball bearing system of the spring guide got wedged inside the piston. Very odd.



After I released it

[ThunderCactus]

Ive seen it twice and heard of it no less than 4 times in the last 11 years

[LT Teach]

Alright, we learn every time we tech. One more possibility to add to my troubleshooting list.

[lurkingknight]

the vfc spring guide can loosen and the gaps in the bearing plates and shaft can open up, letting the spring slip off the perch into the gap, this will lodge the spring in the piston or jam the piston in the gearbox. Solution is to loctite the central shaft on the guide. you can tighten the shaft with a slotted screwdriver with the guide in a vise. Be careful not to torque too much, the pins on the back will snap.

I've seen this exact issue twice.

[LT Teach]

Cool Lurking, thx.