Setting the size of a model or entity

I’m if there’s a code that could shrink a model in lua code. I don’t want the hitbox and collisions cause I already have it below.

self:PhysicsInitBox(Vector(-6,-6,-6), Vector(6,6,6))
self:SetCollisionBounds(Vector(-6,-6,-6), Vector(6,6,6))

I just want to shrink the size of a combine ball so it looks like a bullet. I searched it up on gmod wikipedia but it gave me crap links. Your help would be greatly appreciated.

SetModelScale on client?