The mindset of your average, garden variety Democrat/Liberal/Leftist is to keep the good of the whole of society as the primary goal. To that end, I will dispense with the standard pro-freedom arguments that always fall on deaf ears, and argue profreedom from a statist point of view.
Of course, the inherent danger is that our shooting hobbies will be used to forward a statist agenda, instead of counter it. However, the goal of this post is to make the typical antigun statist take pause and think about how the presence of guns are good for society as a whole, has no tangible negative effect, how gun control is bad for society, or has no tangible benefit for society.
Assault Weapons.
To argue for an Assault Weapons Ban, one first must be able to define what an assault weapon is. The 1994 AWB defined an AW as: "a semiautomatic firearm that can accept a detachable magazine and has more than one of several specific military features, such as folding/telescoping stocks, protruding pistol grips, bayonet mounts, threaded muzzles or flash suppressors, barrel shrouds, or grenade launchers." However, there has been considerable talk about enhancing the definition of assault weapon, because the original ban wasn't good enough. It wasn't good enough because law abiding, peaceable citizens have been able to buy weapons that lacked features such as the bayonet lug and a collapsable stock. Because of the AWB, hundreds of thousands of people who never would have taken an interest in the weapons now own one or more of them with no discernable harm to society. It cannot be argued that ownership of a so-called "assault weapon" by the ordinary law abiding noncriminal poses any kind of danger or does any harm to society.
The National Instant Check System has been tasked with weeding out the criminals, underage and those who have been involuntarily committed to a mental hospital. Once the law is made, the same thing doesn't need to be made illegal multiple times. The categories of prohibited purchasers were created in 1968, and advances in technology were utilized in 1994 to make the process much more efficient and consistent. The AWB was NOT tasked with keeping weapons out of the hands of those who have no business with guns.
Conclusion: Assault weapons do not tangibly harm society, and banning them does not tangibly benefit society. However, the buearocracy involved in policing them takes resources away from the real causes of crime, which IS bad.
Concealed Carry.
Many people will think of criminals carrying weapons, when concealed carry is mentioned. However, criminal possession of weapons is already prohibited, so legalizing concealed carry for law abiding people will not mean that criminals are authorized to carry. Criminals by their very definition do not willingly obey the law. Law abiding people by their very nature do not commit crimes. Thus, permitting law abiding people to carry with them discrete means of self defense has no tangible harm to society. Since criminals do tangible harm to society, anything real or conceptual (ie, unprovable, since statistics aren't kept on crimes that didn't happen) that allows law abiding citizens to reduce that threat via deterrant and force cannot be bad. Laws that prohibit people from carrying the toolos to defend themselves against criminal attack are immoral and inappropriate.
Closing the Gun Show loophole.
This ostensibly is a good thing, however, keeping in mind that criminals do not obey laws, making it illegal to conduct a private transfer of firearms without a background check would have no effect upon criminal activity. The same problems - that criminals either steal guns or buy from a black market after getting rejected in a NICS check - would still exist. There is no tangible societal benefit to closing the gun show loophole because it would not havce the advertised effect. It would simply be ignored by criminals.
Gun Registration.
Any benefit gained from registering guns would be far outweighed by the economic costs of the program. The benefit would be that all registered gun owners would be known, and all registered guns would be known. The issues would be that a majority of gun owners would simply fail to comply with the required registration. Forcing compliance would bring active defiance, which would mean bloodshed and paperwork. Requiring gun registration would cause much more harm than good, on a societal AND personal level. Oh, did I mention that the criminals would ignore the law, and be ignored by the law, in the haste to get the law abiding people registered? That can't be good for society.
You might also note that in the statist's quest to create a sustainable society, they are turning to controls which seem good, but have doomed previous societies to failure. They are turning away from the lack of government enforced control that made this country great.
Even their ideas of a 'right' is in fact a civil right, which is granted by a society that has the resources to grant it. They don't really acknowledge the idea of natural rights, because it doesn't have relevance in a social context. They embrace certain amendments of the Bill of Rights, but not because the right exists for its own purpose (ie, the benefit/pleasure of the individual).
Don't make them play your game. Beat them at theirs.