255 GS

Research notes

The .255 GS (Giani Special) was developed c2010 by Vittorio Giani, a gunsmith of M.A.G. Italia di Giani & Co (Manifattura Armi Giani), owned by Vittorio and his brother Marcello Giani. It is based on the 6.5 x 55 Swedish Mauser (SC64) with an improved 70° shoulder and necked down slightly to use a .255in (true 6.5mm) bullet. The .255 GS, was CIP registered on 26 May 2010. This is very similar to the 257 Arch wildcat developed about 1980.Custom made rifles in this caliber are available from MAG arms as custom products. Custom loads by MAG are loaded with 100 grain Barnes TSX bullets and develop about 3300 - 3500 ft/sec, using cases made by shm. Giani used Norma brass (norma 6.5 x 55) to fireform cases himself, before properly headstamped brass was available. Most of the small number of 255 GS rifles owners still use fireformed brass cases. .