Use: (noun) the action of using something or the state of being used for some purpose.
}}} (verb) take, hold, or deploy (something) as a means of accomplishing a purpose or achieving a result; employ.
Once one's view of the use for a gun is only to kill, it's a logical consequence that guns not in use for killing are not "in use" at all.
This leads further to another harebrained conclusion: all guns used by criminals in the commission of murder and attempted murder are the ones which we can point to as being in the most "common use" being killing. This is because criminals are the Americans who do the most killing (after those who cut funding for medical benefits and the actions of unmanned aircraft in the Middle East and Africa.)
Therefore, (Reductio ad absurdum,) the very cases gun laws hope to prevent or statistically reduce are those which such laws (by the Senator's reasoning) have the least influence by type and function of the weapon in question.
OTOH, when use is viewed in light of the RKBA, which is the real topic, the right to keep and bear for legitimate purpose should never be contingent on having to employ on a regular basis.
"The right to keep and bear arms (often referred to as the right to bear arms) is the people's right to possess weapons (arms) for their own defense, as described in the philosophical and political writings of Aristotle, Cicero, John Locke, Machiavelli, the English Whigs and others."
http://encyclopedia.thefreedictionary.com/Right+to+Keep+and+Bear+Arms