Thanks Germanunkol for helping!
I changed some thing in the script to make sure it doesnt happens again...i put more wait(1) in some steps...maybe something had happed in wrong order, not sure... but for the next demo i think it would not happens again.

About the mesh deforming, later i will try to make it better...the mesh deforms inwards in direction to the model´s origin, but I will try to make it go inwards but using the normal direction. I think it would be better! also put some kind of limits to the damage... in this demo you can shoot things until they almost disapear!! and sometimes they do....hehe !! very funny...

Right now i have finished to ajust the position of the new arm´s model i am using for the player. Next demo the player will be holding the guns correctly!