Caps, Then and Now?

[Norinco]

I remember hearing a while back that percussion caps were much more sensitive back then (19th century) due to the different compounds they used. I think back then they used fulminate of mercury or lead azide, with no need for a frictionizer. Anyone got knowledge on this issue?

Thanks

 

[Bill Hall]

I've only read of mercury fulminate being used all down through history, but that may just be the author's generalization.

I have read that during the early days of cap use, the brass used tended to be too thick and caused some injuries due to blowing apart and turning into shrappnel. Thinner foil was tried with success, giving us what we have today. Bill

 

[Norinco]

What's the compound used in modern caps? They are advertised as noncorrosive, so I would assume whatever is used in modern, American, centerfire primers.