ASCL's initial concerns appear to be unfounded, and it says now that heads in England are happy with the new arrangements and the relative peace of mind they bring as stabbings and shootings continue to plague inner-city areas. But the National Association of Head Teachers Cymru still has some reservations.
"I must admit I would think twice about tackling a pupil believed to be armed," says its acting director Iwan Guy,
It must be said that schools in Wales are far from the becoming the high-security risk zones of the United States, or indeed the scanner-at-the-ready welcoming parties found increasingly at the gates of some English schools.
The National Behaviour and Attendance Review report said there was evidence of worsening behaviour, particularly among younger pupils. But the report still concludes that most schools are well ordered, with low-level disruption the biggest problem. However, isolated incidents of weapon carrying are rising steadily, and schools have to respond.
Knife-wielding and gun-toting teenagers have not yet infiltrated Welsh society. But the threat has to be taken seriously. The dilemma that heads - or even teachers - will have on the spur of the moment, is whether to become a have-a-go-hero or to dial 999.