
Melinda Sue Gordon/Paramount/"Terminator Genisys"
Arnold Schwarzenegger sporting a shotgun in "Terminator Genisys."
Any movie you see that features a weapon, whether a knife or a rocket launcher, has someone behind the scenes who is responsible for its safekeeping at all times.
That person is often called a weapons master but sometimes goes by the title armorer, weapons specialist, or weapons handler.
The position is a fairly new one in the over 100-year history of cinema.
For decades, prop masters were responsible for the dummy weapons used on movie sets. But around the 1980s prop departments began to hire people who not only would focus on the fake weapons (which either fire blanks or don't fire at all) and the safety of the cast/crew, but also have encyclopedic knowledge of the weapons used for the film.
Harry Lu, a 25-year vet of the movie business, was one of the first people given the title of weapons master. Director James Cameron pegged him with the title during the making of 1991's "Terminator 2: Judgment Day."

Paramount
Harry Lu on the set of "Terminator Genisys."
Lu's most recent work can be seen in "Terminator Genisys," in theaters now. And as he told Business Insider, one of the biggest challenges on the film was finding a suitable gun for the film's female lead, Emilia Clarke, who plays heroine Sarah Connor.
"The original script called for a gun that," realistically, "would be way too big for Sarah Connor to be lugging around," Lu told Business Insider. "We ended up giving her a gun that by the time shooting started she would be able to handle with no problem."
To get Clarke prepared to use guns in the film, Lu had Clarke go on a training regimen similar to the one he gave Linda Hamilton (who originally played Sarah Connor) in "Terminator 2."

Paramount Pictures
Emilia Clarke also likes a good shotgun in "Terminator Genisys."
As "Terminator Genisys" varies in time - traveling back to 1984 when the franchise's original film, "The Terminator," was set, as well as taking place in 2017 and 2029 - Lu also had to go over the script before shooting began to make sure the weapons were authentic to the era in which they were seen being used. Especially in regard to the past.

Melinda Sue Gordon/Paramount/"Terminator Genisys"
Jason Clarke, left, and Jai Courtney with weapons from the year 2029.
Lu estimates that around 700 weapons were used on "Terminator Genisys." And though there is plenty of danger and excitement that goes into making sure all of those are used safely and properly on set, there are times when being a weapons master requires just making sure the weapons look their best.
"In the armory scene," said Lu, recalling a scene in which the Terminator (Arnold Schwarzenegger) brings Connor and Kyle Reese (Jai Courtney) to a large bunker of guns he has amassed, "that alone had 200 weapons. And me, my son, and another person had to wipe them down every day."