Hello,
I making the half-life remake on Roblox and I try to import weapon to the blender, and I successful import to Roblox studio but I can’t animate the gun(This model is from Half-life Black mesa source)
However, I can animate a gun on Blender(vertex rig?)
Epic is right, please do not rip models. I would recommend trying to recreate that gun yourself if you want it in your game, as it would give your game a more personal touch.