Jim Armitage: Revulsion at latest US massacre, but don't expect investors to flee

Global Outlook: A total of 47 per cent of households own a gun, up 6 per cent on two years ago

Clint Eastwood with handgun in his Dirty Harry role (Warner Brothers)

Before getting too het up about the evils of America's gun lobby after the Connecticut school massacre, it might be worth checking your own investments here in the UK first.

You could be rather surprised to see that Barclays is listed as a shareholder of the two big, stock market-quoted gunmakers – Smith & Wesson and Sturm Ruger.

A few other names in the British investment world are also backers of both firms: the Fleming Family & Partners' US Small Cap Equities fund and Mayfair-based fund GSA Capital Partners to name but two.

Small stakes all, but stakes nonetheless.

Meanwhile, with slightly more skin in the gun game is Schroders Investment Management, holding 58,400 shares – about $2.5m (£1.5m) worth – of Sturm Ruger, maker of "rugged, reliable firearms", according to its marketing twaddle. And the leafy-sounding Oxford Asset Management has $4.3m of its clients' money in Smith & Wesson.

Morality aside, you can understand why these stocks have been so popular. Shares of US gunmakers have soared in recent years as sales have risen. There really is truth in that old adage – when the economy's really bad, invest in guns, ammo and tinned food.

But the shares have taken a hammering in the week since the tragedy in Newtown. Smith & Wesson is down 10 per cent and Sturm Ruger 8 per cent while Cabela's, a big gun retailer, fell 5 per cent. And those slides were after a slight recovery in the middle of this week.

Perhaps Wall Street isn't so sure they're a great investment after all.

Or, as Cai von Rumohr, an analyst at Wall Street brokerage Cowen & Co, says: "The Newtown tragedy is a potential game changer."

Hedge fund giant Cerberus said it would put up for sale its holding in Freedom Group – maker of the Bushmaster rifle allegedly used by the Connecticut killer. One of Cerberus's biggest investors, the California Teachers' Retirement System, had hinted it was a tad squeamish about owning a company whose product had just perhaps killed so many primary school kids. I wonder how many teachers in California knew that their savings were invested there in the first place?

Other share sales may follow when the teachers of New York and Texas wake up to the fact that their pensions were invested in gunmakers too (well, maybe not in Texas. Most teachers there were probably packing heat long before the Connecticut shooting).

There have, of course, been many massacres by crazed US gunmen in the past few years – four since July - but the gunmakers' shares have kept on rising. However, bears on Wall Street say Newtown is different. So many dead. So many of them young children.

This time, they say, curbs on assault rifles such as the Bushmaster, long called for by many Americans, might actually come to fruition. Likewise, those huge ammunition clips capable of holding dozens of rounds could well be banned from being sold to the public too.

Even for the likes of Smith & Wesson, best-known for handguns like Dirty Harry's famous 44 Magnum, this could be an issue. Cowen & Co say "tactical rifles" – Rambo-style semi-automatics to you and me – make up about 20 per cent of Smith & Wesson's sales – and that is excluding those to the police and military.

Perhaps we should look at how gun sales were affected when the last ban on assault rifles came in. This law lasted for 10 years from 1994. In the run-up, people flocked to their gun shops, just as they have been doing this week, in anticipation of new curbs. But in the three years afterwards, sales plunged by a third.But more intriguing is whether the overall social attitude to guns will really change. And will the laws, likely to be enacted in the spring at the earliest, be particularly stringent? I'm not so sure.

We're talking here about a country where a total of 47 per cent of households now own a gun, up 6 per cent on two years ago. More women are buying them, and for nuts with more than one firearm, the average is now eight per person.

Undoubtedly, owning a gun has become increasingly normal as slick marketing execs have taken top positions in the boardrooms. Take Smith & Wesson chief executive James Debney, a Brit who sold Bacofoil before joining the gun world last year. He told a conference in September he wanted his firm to become more of a "consumer products company".

"What we get excited about is that expanded user base and the level of social acceptance that we see now out there," he explained. "It is socially acceptable to carry a firearm, more so than before – to carry a firearm for protection, have one at home for protection, go to the range to shoot as a pastime, as a hobby."

That conference was a few weeks after James Holmes killed 12 and injured 58 in a cinema in Aurora, Colorado, during the screening of the new Batman movie. Holmes used a Smith & Wesson assault rifle with a 100-round clip on those innocent cinemagoers, but it jammed after firing only about 30 bullets. Bad advertising for Debney on all fronts, I'd argue, but still sales rose.

Debney also talked at that conference of an exciting new "younger demographic" that "grew up playing video games" and was "very interested in firearms". Hmm… people like Holmes, who told a fellow prisoner last month that he "felt like he was in a video game" when he killed those people. Or Newtown shooter Adam Lanza, a big Call of Duty fan.

Debney and his fellow marketing men clearly won't be using such truthful language for a while. But the $1bn question is for how long will this period of sensitivity last?

Will America's memory of the Connecticut killings endure long into the new year? I'm not so sure. And if the amnesia returns, don't be surprised to see the gun lobby water down any new laws.

As history has taught gun-loving investors time and again, you should never underestimate the NRA.