Spawning a ragdoll?

[Fidchell]

I'm currently working on a gore/dismemberment mod, but I'm at a loss on coding and I need some help. I have a template that's already been made by a friend, but he's busy working on another project and I'm trying to progress the mod. I'm able to do the modeling and such in a way similar to headspack. I've reached a point where I am making the entire body of the Combine split in half around the stomach area and I'm not sure how to spawn a ragdoll...properly. The coding that's been done by my friend makes the piece of the body being separated stand in place as if it was still attached to an invisible model. The physics are greatly messed up as well. Here's a piece of the code:

         if ( hitgroup == HITGROUP_RIGHTARM ) then            if (dmginfo:GetDamage()* math.Rand(0.75,2) >= CriticalDamage) then
            ParticleEffect("blood_headshoot",pos,Angle(0,0,0),nil)
            
                             if (npc:GetModel() == "models/combine_soldier.mdl") then
                 
                      npc:SetModel("models//arms/combine_soldier_armless.mdl")
                                          Gib(npc,pos,HeadshootGibAmount,HeadShootForce,direction)
                                                                                 RightArmGib(npc,pos,"models//arms/combine_rightarm.mdl",HeadShootForce,direction)
                     end
                end
                end

Here's the function that is supposed to spawn the piece of the body being shot off:

 function RightArmGib(ent,pos,headmodel,force,direction) 
    for i=1, 1 do
    
             if (GetGlobalInt("gibsnum") >= GetConVar("g_maxgibs"):GetInt() ) then return end
     
         local gib = ents.Create("prop_ragdoll")
         gib:SetPos(pos + Vector(0,0,10))
         gib:Spawn()
         gib:Activate()
         gib:SetModel(headmodel)
         gib:SetAngles(ent:GetAngles())


         local phys = gib:GetPhysicsObject()
              if !phys:IsValid() then
                                        return
                                        end
         phys:ApplyForceOffset(direction/2,direction)
                     gib:Fire( "kill", "", math.random(GibLifetimemin+3,GibLifetimemax+4))
     end
 end

This specific style of coding leads to no arm and the console errors:

Attempting to precache model, but model name is NULLRagdoll () has no model!

Is there a better way to spawn a ragdoll? I'm sure the model itself is just fine...