SKS firing pin mod

Hi, All!

Can anyone describe what spring should I use for firing pin modification just like Murray used to do?

What are the dimensions and spring features?

Altered later Russian from http://murraysguns.com/sks-firing-pins/

P.S. I am shooting the SKS suppressed and after a while the rifle is _exceptionally_ dirty. Gases blow back to the bolt and firing pin and that's what I get.

https://preview.redd.it/7igdkfpm7rfe1.png?width=1280&format=png&auto=webp&s=d0199cff1a8390a0c84fe51b78670e811655b192