Removing Buttstock From Valmet 412ST

[GrumpyGramps]

Does anyone have information on how to remove the buttstock on a Valmet 412ST shotgun? Looking at the buttstock screw it does not appear to be a standard hardware design. Is there a special tool required and if so does anyone know of the availability? I have read that the 412ST had a special "quick change" buttstock attachment, but don't have any details.

Help!!

 

[rmw]

I have an older 412 and had a newer Tika and they both just took a metric Allen wrench

 

[GrumpyGramps]

A 5mm allen key fits the screw. The end of the screw was worn and I could not visualize the hex. Looked like a circle.

Thanks