Framework problem

So I made a framework and I play an animation on it which was made from a full humanoid (all limbs on it) now the frame work is 2 arms and I play animation which was made on a dummy on these 2 pairs of arms but only 1 arm works, so I wanted to ask if this is because I animated on a wrong type of rig or the script errors.

local run = game:GetService("RunService")
local cam = workspace.CurrentCamera

gun = game.ReplicatedStorage.Arms:Clone()

gun.Parent = cam

local animation = gun.Animation
local WalkAnim = gun.Humanoid:LoadAnimation(animation)