Hi All.
Thanks for taking the time to read this inquiry.
I ran into this problem where the first round would fire (No issues) and then the second round would "Jam" or fail to fire. I have a few pictures attached to help with the visualization.

Some background info:
- This is my first SKS and today is the first time firing this rifle using stripper clips running Barnaul HP 7.62x39 rounds. It is fed from the top using stripper clips.
- I am running a Fab Defense stock that I assembled myself.
- First few rounds were flawless and If I recall correctly, this issue began to occur at the last round but sometimes it would occur in the middle of 5 round stripper clip (In Canada, we are pinned to 5 rds).
- Rifle was cleaned using brake cleaner but the bolt assemble was not touched. The firing pin moves freely (Up and down).
WHat could be causing this and how would I mend this to prevent it in the future?
Thank you for your comments and suggestions.