Solved
Mass effect 3 gunsmith achievement
It reads "GUNSMITH - Upgrade any weapon to level 10". In the Old ME3 this was for multiplayer achievement. There is no Multiplayer in Legendary Edition. In old ME3 single player has 5 levels to upgrade and multiplayer has 10 levels to upgrade and in Legendary Edition single player has 5 levels not 10. Thanks
You can upgrade weapons up to Level 10 in NG+.
