@iluminatetheskyI checked and the Lewis gun is behind a rank 10 unlock same with other weapons that looks like i should have gotten from the enlisted offer that i got unlocked and in my Library in origins.
The Enlister Offer gets you weapons that you can use in Battlefield 1.
It has nothing to do with Battlefield V, and does not unlock weapons for you in Battlefield V.
I could have sworn the fine print said something along the lines of "for use in Battlefield 1, and later, Battlefield V".
I'm not near my ps4 atm so I can't confirm but I was always under the impression we could use them at some point.
