Hubertus was a trademark coined by Imm. Meffert near the end of WWI or when Brno Meffert took the reins. Circa 1930 Imm. Meffert offered a Hubertus version that was lightweight, but lightweight from removal of metal from non-crucial areas to reduce the weight. Then in 1931 3 blocks of Duralumininum(Dural/Leichtmtetall/Alumininum/Aluminum), more than likely sourced from Dürener Metallwerke, for production of the Hubertus Dural/Leichtmetall drillings.

Interesting side note that Sauer stuck with all metal sporting weapons.

http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=259889&page=1

Kind Regards,

Raimey
rse