Ringing is more a function of helmet design and construction, rather than of the gauge material. My 12 ga. stainless bascinet rang more than anything I had ever run into, enough to be painful. The padding methodology was the key to managing that problem.
I recommend viscoelastic polymers combined with foam neoprene rubber for helm padding. I've found that combination to be very effect for many years through a great many bouts and melees.
Some great stuff in the video. But it is worth emphasizing that a lose helmet or a bad chin strap turns your helmet into a blunt weapon against your own face. I'm glad to learn that lesson from a black eye rather than my clan's traditional broken nose.
I remember seeing a video you posted at Midnight Madness more than a few years ago and you mentioned taking a spear to the jaw in a battle. Was this the helm you wore at the time?
