WRONG - this is the problem with MA people. You don't have to "show that what you did was reasonable".
They have to PROVE that what you did was UNREASONABLE. BEYOND A REASONABLE DOUBT.
Further, in a dwelling, you do not have to retreat, provided you reasonably believe that you or someone else is at risk of grave injury or death.
Weapons are not mentioned because there are many ways to use Deadly Force.
Take a look at the MA Jury instructions in this link. It may open your eyes.
http://www.mass.gov/courts/courtsan...s/criminal/pdf/9260-defenses-self-defense.pdf
Either way. Anyone who counsels their wife/girlfriend/responsible children not to use an accessible firearm in self defense, because they are not licensed, is an idiot of the highest order, with absolutely no understanding of the basic ethical concept of self defense.
If someone is in my house unlawfully and intends to harm me or my family, my wife and I unleash holy hell upon that person(s) to the best of our ability. Period. End of discussion. This philosophy is perfectly consistent with the laws of the United States and the Commonwealth of MA.