Unless Bohemia have created a new round that I'm not aware of, the Mk14 EBR uses 7.62 x 51mm rounds, and as the MXM uses the same magazine as the Mk14 EBR I'd assume it should as well. Unsure if a typo or intentional.
- Legacy ID
Look at 7.62mm magazine info.
I'm actually cool with the round being listed as 7.62 x 45 mm... at this point 7.62 x 51 mm seems almost boring by now to see in the future warfare-themed game, and it was actually funny to see a however-subtle case of "CZECH STRONG" in the alpha.