German Anti-tank rifle identification

Solothurn is indeed a Swiss company.  However, it started out as a wholly owned subsiderary (sp) of the German company Rheinmetall.  It was a way for German manufacturers to get around the restrictions on the design and production of war materials placed upon Germany by treaty at the end of WW I. Rheinmetall designed the weapon and Solothurn produced it.

Hey, thanks for pointing that out! Very interesting!

Note the GIGANTIC trigger/trigger guard.  You fired it with your first TWO fingers.

These were sold to US Civilians before more restrictive gun laws made their way into the books. 

They were very reasonable, too.

 

Thank you, sir!

It's a Solothurn 20mm anti-tank rifle S-18/100.  They were produced by Switzerland and used by the  Germans, Italians, Hungarians and the Finns. 

Here's another shot: