Why the gun-grabbers are wrong, in a nutshell:
It doesn’t matter what your lifestyle choices are, there are evil people out there who want you to die for them. Evil doesn’t care about laws. In this particular case we are talking about a subset of ideologically inspired killers so motivated that they weaponize pressure cookers and regularly carry out gun massacres in countries where regular citizens aren’t allowed to own guns.
I already addressed mass killings and all the various regularly proposed gun laws in 2012 after Sandy Hook. This ended up being one of the most widely read articles ever written on the subject. If you want to have an in depth look at these events and how all the regular gun control proposals work, read this first: http://monsterhunternation.com/2015/06/23/an-opinion-on-gun-control-repost/
And everything I want to say about the typical media/government response to these atrocities, I said after San Bernardino: http://monsterhunternation.com/2015/12/03/guns-and-vultures/
When evil people attack, you can either be in a position to do something about it, or wait for somebody else to come and save you. Being armed and trained doesn’t guarantee your safety any more than wearing a seatbelt doesn’t mean you’ll live through a crash, or owning a fire extinguisher means your house won’t burn down, but it may help.
Please read that first link where I go into detail how mass shootings work and how they usually unfold. We see every time that the best way to end a mass shooting event is an immediate violent response. If that response comes from somebody already present, the body count is usually lower. If the response comes from the police, then there are usually more casualties simply due to the response time.