king arms svd piston issue

[Chevaliernoir]

I'm currently restoring a king arms spring svd. I'm having an issue with the piston. When I fire the gun the piston struggles to move through the cylinder. I have tried everything from replacing the o ring to cleaning the piston and cylinder. does anyone have any idea what might be causing the problem and how I can go about fixing it?

[airsoc]

Re: king arms svd piston issue

Lack of lubricating grease? If its struggling thats my first guess

[Chevaliernoir]

Re: king arms svd piston issue

Tried thoroughly lubricating it and still no change

[sniper1982]

Re: king arms svd piston issue

spring is knackered?

[Chevaliernoir]

Re: king arms svd piston issue

That was one of my thought. The o ring doesnt seem to fit into it very well into the piston either which could play a big part

[Chevaliernoir]

Re: king arms svd piston issue

Just ordered a new spring. Will see if that makes a difference

[sniper1982]

Re: king arms svd piston issue

if the o-ring is over stretched that can cause the same issue. pop by plumbing section in b&q or homebase and get a replacement.

[Chevaliernoir]

Re: king arms svd piston issue

New spring and o ring haven't helped. I only seem to have the issue when a bb is loaded and ready to fire. Any ideas?

[Chevaliernoir]

Re: king arms svd piston issue

With further inspection it seems that something is jamming the bb in the hop unit

- - - Updated - - -

Problem found. The hop rubber had torn and a fragment had got stuck with a bb in the inner barrel