I can think of a bunch of answers
"I'm not Rambo, I'm Napoleon"
"The little voices told me I'm John Wayne"
""You're wrong sir, I am the reincarnation of Wyatt Earp"
"You don't like Glock?, ok next time I promise it will be a 1911"
"Yes, it's a gun!, is that a toupe?"
Or just stand up and yell real loud
"Nothing is over! Nothing! You just don't turn it off! It wasn't my war! You asked me I didn't ask you! And I did what I had to do to win, for somebody who wouldn't let us win! Then I come back to the world, and I see all those maggots at the airport, protestin' me, spittin', callin' me a baby killer and all kinds of vile crap! Who are they to protest me?! Huh?! Who are they?! Unless they been me and been there and know what the hell they yellin' about!"
"They drew first blood , not me....."