I have to mention Ole Horsrud, inventor of the gun that was sold as the Sears Ranger and the Marlin Model 90 O/U. It had many technically advanced design features when it was introduced in 1936/37. ( See article entitled, "A Case Study in Ingenuity; The Marlin Model 90," in the 2010 Gun Digest, Page 66.) My favorite upland bird gun is a 16 ga. Model 90.
