Search the world’s information, including webpages, images, videos and more. Google has many special features to help you find exactly what you’re looking for. Dec 2, 2007. In 1932 the bolt was strengthened to permit use of the new high-speed.22 ammo ; these rifles were identified by an “HS” prefix to their serial numbers. By now, at $26.50, the new, improved Marlin 39 was the most expensive.22 rifle on the…