Xausa

Couple things I see here

Your rifle, the missing pin - replaced by a screw...

Did someone take a tap and thread your takedown pin journal to accept a screw?

The pin pictured in Rothhammer's post above, it's a wedge.
I would expect these pins to be fitted to their rifles, similarly to how forend iron pins tend to take a bit of fitting. That image would be a great guide, but I wouldn't be surprised if some more or less material somewhere along that tapered pin would be needed for a proper fit.