york city with bill weir. Not columbine, nor virginia tech, nor the gaby giffords shooting that took six lives in tuscan had much effect on the gun debate if this country. But there is nothing like... See More
york city with bill weir. Not columbine, nor virginia tech, nor the gaby giffords shooting that took six lives in tuscan had much effect on the gun debate if this country. But there is nothing like the slaughter of 20 first graders to help people focus on an issue. Many on both sides of the second amendment debate wonder tonight if this one is big enough to actually change the big business of guns in t country long-term. Darren rovell found some interesting early indications. Reporter: At a gun store in san gabriel, california, just outside of los angeles, business was brisk today. Customers buying guns and ammunition, making sure they can get what they want now. The u.S. Firearms industry is breaking all kinds of sales records. Now more than a $30 billion business with so many different people buying guns, that it's impossible to profile the typical gun owner. I need your signature. Reporter: People like this stay-at-home mom. This is the first gun I have ever purchased. I never thought I would be purchasing one, but my husband does have one. Reporter: Edgar hernandez was just out window shopping. I came in to look for a new long gun for my collection. Reporter: Pete has owned this store for 30 years. There's more and more first-time gun buyers than I can ever remember. People who 20 years ago would have never dreamed of owning a firearm. There you go. Ready to rock 'n' roll. Reporter: In the wake of the massacre at newtown, the people willing to consider putting their hand on the trigger has risen. The media and the government are talking about more gun legislation, so therefore, they're deciding well, perhaps i should take action now. Reporter: Despite the cash registers ringing, it's not an easy time to be in the gun business. Walmart, the nation's largest seller of guns and ammunition, has pulled their version of the bushmaster semiautomatic rifle similar to the one used in the shooting off its website. Outdoor retailer cabella's has decided not to carry the gun used in the shooting in its one store in connecticut. While dick's sporting goods is taking it a step further. Company temporarily suspending a whole category of modern sporting rifles at its more than 500 stores in 44 states nationwide. Many public companies are torn between showing sensitivity towards what happened in newtown and trying to make a profit. What do you feel like the responsibility is for the companies, their fiduciary responsibility versus being sensitive? The sandy hook tragedy profoundly affected a large number of americans, so I think they're going to tread lightly and do their best to challenge both of those obligations. Their obligation to be respectful to the victims and also their desire to make as much money as possible. Reporter: Despite the jump in sales, investors haven't felt positive about making a stake in the gun owners themselves, who continue to get pounded on wall street today. Shares of smith and wesson dropped 10% today. The stock has dropped 20% since friday morning. Another gun company, sturm ruger down nearly 18% since friday. When the california state teachers retirement system, the largest educator pension fund in the realize it invested in bushmaster, the gunman's rifle brand -- we were frankly horrified to learn on monday morning that within our investment portfolio we owned a company, or a slice of a company that manufactured one of the weapons that were used. Reporter: After the teachers threatened to pull its sizable investment altogether, that firm announced today it would sell its gun business. They are saying it was a financial decision. As a firm, we are investors, not statesmen or policymakers. Our role is to make investments on behalf of our clients. The company said in a statement. Back at the gun shop in california, pete shows off a version of the ar-15 rifle he has in stock. Similar to the weapon that was used in the connecticut shootings. He is unapologetic. The second amendment isn't about hunting guns. It isn't about target shooting. The second amendment is about the power of the people to protect themselves from a government that has become oppressive. Reporter: Politics versus profits. How that's resolved will determine what will be sold in the future. For "nightline," I'm darren rovell in new york.
This transcript has been automatically generated and may not be 100% accurate.