Because the original Star Wars episode #4 (A new Hope) was filmed on a low budget most of the props were everyday items. It was a fun game "tagging" SW hardware for it's real purpose.
Let me see what I can remember.
Han Solo, Broomhandle mauser with a fancy flash hider.
Princes Leia, A Russian "Vostok MU" target pistol In .22 RF. (Sold as "Margolin" in the US)
Sand People "blasters" Lee- Enfield smoke grenade launchers.
Storm troopers: a mix & match.
Street-legal sterling semi-auto short carbines with a 10 round magazine & a "single point" Armson OEG red dot sight, an MG 34, a few Lewis guns.
Darth Vader:'s light saber. A MPP "Micropress" bulb flash gun (The big ones like WEEGEE had hanging on the side of a big old press camers.)
The fuelling bowsers for the Millenium Falcon? Jackhammer compressors with a sound reducing shield.
Chewbacca's "crossbow"? beats me but it had a No4 Lee Enfield muzzle & frontsight on it.
Curio break. What is inside the bottom of Darth Vader's light saber when you unscrew the black base cap?
How much did it cost when bought at retail?
Answer in a couple of days..................