Martin Hagn was born in Munich, Germany in 1943.  From age 7 to 9 Martin attended public school. Thereafter, from the age of 10-14 he went to a Catholic boarding school  before attending the Gunmaker School in Ferlach, Austria from age fourteen to nineteen.  In Ferlach, he completed four years of gunmaking training and one year of stockmaking.  Upon graduation from the Gunmaker’s School, Martin worked for Griffin & Howe in New York, where he stayed until 1966.  After leaving Griffin & Howe, Martin worked for Howard's Gun Shop in Alaska. After returning to Germany in the spring of 1967 Martin worked for Kettner Company in Cologne, Krieghoff in Ulm and Oberhammer in Cologne, to gain more experience.  In 1969 Martin achieved his Masters degree in Gunmaking in Munich.  

From 1970 to 1985 Martin operated his own shop in Germany where he focused on building the Hagn Single Shot rifle of his own design for which he is now well known.  He also made stocks for Hartmann & Weiss in Hamburg and custom fitted stocks for Olympic Gold Medalist Conrad Wirnhier.

 In 1985, Martin moved to Canada and has been building custom rifles for customers world wide ever since. While Martin specializes in his patented single shot in four frame sizes (see below for more information on the action), he also builds custom rifles based on Mauser actions and does custom stock work.  

In 1986, he joined the American Custom Gunmaker Guild and is also a member of the German Master Gunmaker Guild.