Shoot them in the leg and say damn I guess you're right. Or tell them it is not the place of an intrusive public official to decide what is the best way for me to protect my family. I enjoy my rifle and will be keeping it.
I usually show them a photo of an M1-Garand. It is pretty, has a nice wooden stock and to someone who has little to no experience with firearms resembles a hunting rifle.
Once I explain that that is the Gun we won WWII with and that it is significantly more powerful than an AR-15 it tends to open their eyes a bit.
But for the most part I have given up arguing with anti-gun folk. Their arguements are based entirely on emotion. If a gun looks scary then it IS scary. Attempting to explain that an AR-15 is no more powerful than any other gun chambered in .223 Remington is a losing gambit because they are not playing the same game we are.
Attempting to explain to someone for whom the government is a comforting pancea that the REAL purpose of the Second Amendment is to secure the other rights of the people through force against a tyranical government, or that the Battle of Lexington and Concord occured as a result of attempts by the British to confiscate the arms and poweder of the colonists and is an example of the same is useless.
Try showing these two pictures to an anti-gunner
Then ask which one should be banned.
The top rifle is chambered in .577 Tyranosaur one of the most powerful shoulder fired rounds in the world.
The bottom is of course the ubiquitous M-4 carbine available in a semi automatic civilian version.
I can about guarantee that the anti gunner will pick the bottom rifle.
Then show them these
The largest round in the second picture is the same as the SMALLEST round in the first picture!
The smallest round in the second picture is of course a .223 Remington (5.56 NATO) the round shot by the M-4 pictured above. (I know the .223 and 5.56 are not exactly the same)
It depends. Sometimes I just smile and listen. Other times I just shake my head in agreement.
When they really get into it I tell them I think that only the police should have guns. If they don't respond I add in a deadpan "When seconds count the police will be there in a couple of minutes. I often get a perplexed look.
If they respond that they agree that only the police should have guns then I kick it up a notch and tell them that guns are so bad I don't think even the police should have guns.
They usually say that the police have to have guns. I ask why. The best and usual response is "because they get the bad guys and the bad guys have guns!"
That's when I just smile and say EXACTLY! Then walk away.
Anti-gunners and "progressive liberal Democrats" are not big on facts and logic.
Now I don't mean to be nasty or anything, but if you don't know how to address this question, you need to educate yourself a bit more, and I do realize that is what you are in the process of doing here. Don't just rely on what other people would say. Educate yourself, form your own opinions, and speak from a position of confidence. In other words, know what your talking about and why. Most of the people asking that question are either ignorant of the subject, or just trying to be a smartass. Of course some are actually interested. You'll know which one is asking the question.
I usually simply say, "This isn't an Assault Rifle. An Assault Rifle is a military-grade weapon capable of selectable fire - semi-auto, three-shot burst, and full automatic, like a machine-gun. This is just a basic semi-automatic rifle. It shoots one bullet at a time, just like any other hunting rifle. It's just easier to point and shoot when it's set up this way, instead of the older style with a straight stock."
I wouldn't mention the fact that the M-16 Assault Rifle should never actually be fired in any mode other than semi-auto. That would only confuse the poor media victim. Use the opportunity to educate, as has been suggested above. Help people understand what the term really means. It may help them get over some of the knee-jerk fear.
If he/she is a "shoot from the lip" type, there's no point in even attempting discussion or reasoned debate. If he/she is the type you can talk to, it's worth explaining the history of the 2nd Amendment, why a standing armed force was called "the bane of liberty," why the Founders intended that all armed force (guns = power) be in the hands of the people. It doesn't hurt to remind them that the police have no duty to protect you; there's plenty of case law on that. Frankly, I believe it's my duty to own a battle rifle and ammo, and maintain a reasonable degree of proficiency.
I keep 2 pictures available on my phone. One of a tricked out Ruger 10/22 with a "sinister"looking bullpup stock completely blacked out. The other one is of a stock 10/22. Just like the one they sell at the local Walmart. After showing them the pictures, I ask which one of the guns do they want to ban. They always have the same confused look on their face. You know the one. It says, why would you even ask that. They say, why that evil assault rifle of course. Well, I then get the chance to educate them about how they are the same rifle. I then offer to take them to the range. They usually get mad. But, I have had a few takers. And a few of them even changed their mind. (just a few) We need to learn to use these opportunities to slowly eliminate the ignorance about our chosen hobby/sport.
I just don't understand people against guns. I have had the arguement that the 2nd ammendment was created in a time of muzzle loading powder rifles for us to stand up against our enemies. Well what is wrong with machine guns now? Our enemies have them and the paper work and ffl licensing to get and keep them are not easy or fast to get. Enemies and criminals have automatic weapons and so do I. The only difference is the ATF and U.S. government says I have a clean record and im a reputable person......and what do criminals and our enemies have to do to get them? Oh yea they don't do any of that.
I usually start with, "Please define an 'assault rifle' for me." They usually said "assault weapon" and that leads to even more fun with the definition.
We can also go to reciting the Second Amendment and pointing out that it is not about hunting but about defense of the nation, community and self (that includes family and friends). The clear meaning is that the militia, you and me, are meant to have the same level of arms as the Army, Navy or Marines. We could get into just how far that goes but it is a very big subject. At the time of the American Revolution the muzzle-loading musket was the cutting edge "assault rifle" of the time. Currently, since it's back in regular service I'll take an M-14, M1A.
A guy was bad nothing me about having a assault rifle. So I asked him what is a assault rifle. His words were AK-47 and AR-15. I told him those are specific models, but what makes it called a assault rifle. He didn't have a answer. The truth is there is no such thing as a assault rifle. It is just a term anti gunners made up to make a certain weapon system bad.
First off, just what classifies a firearm to be an assault rifle? The PRK when I worked there clarified that a sniper rifle was a high powered rifle with a high powered scope, with a magazine of military stature. That just defined my deer rifle, I have bad eyes and I love the accuracy or the .308, and it never hurts to have a few extra bullets, especially if hunting bears.
Besides I have never owned a firearm that has assaulted anyone, now I cannot say the same for myself. Does this mean I will be banned? The problem is the Anti Gun idiots know just enough to make them a nuisance and fail to read all the gun laws and initiatives, they only read the ones they think they can win.