Also not Berezina 12.7mm MG because the Berezina is a river of the Belarus and a tributary of Dnieper River. Berezin is a name. Michail Berezin was a Soviet designer of UB (the Berezin's Universal) and the BS (the Berezin Synchronized) series of machine guns. The UBK, UBS and UBT 12.7mm MGs were accepted into service on April 22, 1941. Just to make it clear.