Last week, The 180 presented a debate over the lineage of a semi-automatic rifle called the AR-15, and whether it matters that the weapon was originally designed for the U.S. military.

The AR-15 is 'restricted' under Canadian law, which means it has to be registered with the RCMP, and can only be used on a firing range. According to one perspective we heard on last week's show, the gun is mechanically similar to other non-restricted weapons, and is only subject to tighter laws because it looks like a military weapon.

The item was presented by The 180's Matthew Lazin-Ryder, who admits, before researching the story, he didn't have much knowledge or experience with guns and gun regulations.

"One of the things that really struck me about putting that story together was how little I knew about the specifics and the gun laws in Canada, and I think a lot of 'city-dwellers' would be surprised at what's legal and what's not in this country," he says.

Turns out, Matthew isn't the only journalist who had to start from scratch when it comes to guns.

Poynter Institute journalism instructor Al Tompkins says as time goes on, each generation of journalists knows less and less about firearms.

Tompkins says the biggest confusion is around the distinction between an automatic and a semi-automatic weapon.

"Quite often [journalists] overstate how often the semi-automatic, particularly the AR-15 rifle, is used in mass crimes. First of all, they don't know the difference between these different kinds of weapons, they don't understand calibres and gauges and it's largely the verbiage they get wrong," says Tompkins.

He says journalists have to cover a variety of issues, and sometimes on the issue of guns they typically think the full picture is being delivered to audiences when both side of the gun debate are presented.

"Sometimes both sides can be misinformed," he says adding that it's a complicated issue full of nuances.

"You can't just get kind of close. You have to get it right because there are so many people who know the subject well and they will call you out on it."

Tompkins says often the best stories — especially when it comes to public policy issues like gun control — come when journalists have enough understanding of the issue.

He says, for example, those who want to regulate the AR-15 fail to state that the AR-15 rifle is rarely used in mass murder. Statistically, Tompkins says, it's the 9 mm pistol that is more common in mass gun deaths.

To listen to the feedback to last week's item, and the interview with Al Tompkins, press the PLAY button at the top of the page