Because I started thinking about which device (nuke vs. lead bullet) was more capable of delivering computational malware, as that would lend itself to more entertaining pun.
But I eventually decided that wasn't a fruitful vein of humour, so I pared it back to mere mention of the weapon.
I.e., even though I no longer jad a reason to prefer the bomber over the pistol for the pun, I stayed with it out of mere joke-planning inertia.
Why mention just one or the other in my original comment?
Well, because, as you probably know, brevity is the soul of wit.
They were clearly referring to the Colt Single Action Army revolver handgun.