Stembridge Gun Rentals
http://www.ar15.com/forums/t_1_5/506928_Whatever_happened_to_Stembridge_Gun_Rentals_.html
My favorite was the flintlock pistol that the Predator tossed at the actor at the end of the second movie.
For the fans, an entire database of all guns in movies:
http://www.imfdb.org/wiki/Main_Page
One of the best is Death Wish 3, the Wildey Hunter!
http://www.imfdb.org/wiki/Death_Wish_3#Wildey_Hunter
I was watching some old western from the 1950s in which the cavalry attack Indians. In the melee, the Springfield rifle bends double, then springs back straight. It was rubber.