Spoiled for Choice not unlock

[!=Me]

i infused every single weapon type and got all 4 legendaries,but no unlock .(No DLC Weapons)

[HoneyDrake]

Common weapons:

3 pistols (Spiker, Fourpounder, Tribunal)
1 SMG (Limp-10)
2 Shotguns (Vopat and Strelak 50-50)
2 Long Range weapons (Rapier, Pepper Mill)

Legendaries:

Double Pistols with a secondary mode (Strelak Verso)
Double mag automated SMG (Constancy)
Shotgun with 2 modes (Heritage)
Sniper Rifle (Sepulchra)

[Alphadoriest]

Infused all of the above and no dice (no DLC).

Only weapons I haven't infused a dozen times over are the legendaries. Could one of those somehow be an issue if I picked it up off a Juliana?

[Alphadoriest]

Update: No idea why, but infusing the Strelak Verso again secured the achievement for me. Odd!

[Ghirahn]

Did you join the arkane outsiders thing?
that does give you a 'free' strelak verso.