Fabryka Broni, the inventors of MSBS rifle, is coming up with 7.62x51mm version of their rifle tentatively named MSBS-7.62. Their modular rifle in 5.56x45mm is aiming to be Poland's Military Issue rifle.
It is still in development phase but it is interesting to see an underdog trying continuously.
http://www.thefirearmblog.com/blog/2016/01/13/fabryka-broni-unveils-7-62x51-msbs/
From: The Firearm Blog