I also find Ian´s theory (presented for the first time at the Gathering in Leeds) about the inherent weakness of multiplate kabuto equally fascinating. In order not to mix up the threads, I thought it best to create a new thread where this specific topic can be adressed in full. To provide some pictures which to some extend support Ian`s theory I start by publishing the pictures of the 16-ken Suji-kabuto from the Tameshi-Zunari thread.
A bullet-test that obviously created enough damage to warrent an extra rivet to stabilise the front of the kabuto.
Then whilst searching the old Interweb, I came across a 62-ken Suji kabuto displaying some serious damage that resultet in some extensive repair. Some sort of impact, quite possible from a bullet has caused this.
A closeup reveals a massive crack between the plates, partly repaired. Looks like a big part of the front has been ripped apart.
This damage could quite likely have caused some sort of injury to the wearer of this kabuto, under true battle conditions.