Following the Sandy Hook shooting, I've been gloomily anticipating an authoritarian knee-jerk reaction to ban some types of guns. I've read libertarians calling for a renewed commitment to the pro-gun message. Despite this, I won't fall for the old trope that the pro-gun movement is somehow libertarian. Libertarians should evaluate each pro-gun initiative on its own merits to decide whether it advances liberty.
For instance, the NRA is clearly not a libertarian organization. Not only are they willing to attack free speech (by blaming violent media for real violence), but they are perfectly comfortable establishing a permanent police presence within schools. That's not to mention their refusal to address any other infringement on liberty, even those that so clearly exacerbate gun violence (such as the drug war).
The NRA has even managed to institute pro-gun policies that directly infringe on liberty. For instance, private institutions are often forbidden from regulating whether guns can be brought onto their real estate, all in the name of "gun rights". One issue of contention right now are the "stand-your-ground" laws, so I am wondering if these laws are libertarian.
On the "plus" side, the obligation to retreat is a regulation on individual behavior that is enforced by criminal penalties, so eliminating it seems to be libertarian. However, since it is only regulating an involuntary interpersonal interaction, I think that it can't really be libertarian or anti-libertarian.
On the "negative" side, many of the "stand your ground" laws over-ride the civil tort system (see Table 1, here), which seems anti-libertarian to me.
This issue is a bit difficult for me. Much of my libertarian preference is based on the idea that we should use the minimal necessary force when dealing with others, therefore I am opposed to the tough-guy spirit behind "stand-your-ground". On the flip side, I a person who stands his ground is not so far out of line that it is necessary to use force against him.
But this is coming from someone who is still pondering whether force is justified to deter theft.
P.S. more information on self-defense laws.