I can claim to be years ahead in the development and testing of advanced NBC kit. At Gutersloh in the mid 80's, I had an NBC suit with the lining removed, a respirator filter with the element removed for easier breathing, and a steel helmet which was, in fact, made from fibreglass (by laying up glass cloth and resin over a real helmet as a mould). The helmet was fitted with the proper inner fittings & strap, and was dressed with cam net and scraps of hessian. Controlled testing, however, showed it to be incapable of stopping a .22 airgun pellet fired from a Webley Senior pistol.
All of these accoutrements were viewed with some suspicion by the RAF Regiment staff who accompanied us on our SH holidays in the German countryside on deployment and Exercises. However, I always think that personal comfort is a great thing...........
And yes, I did have the 'real stuff' close to hand in my vehicle.........
HB