[Firewalker]

I have a SIG 556 Shorty which come with the King Arms Tactical Battery Stock (which is a regular looking collapsable stock with room for a custom battery).

I've played with these kind of stocks before, and all I've ever had to do was pull the locking pin and slide the stock right off the buffer tube.

I've tried this but cannot.

I've pulled my hardest and it's not budging but I don't want to pull too hard in fear of breaking something.

Any advice?

I'm looking to replace the stock to a modstock so I can accommodate regular (eg: not as hard to find or expensive) batteries.