It appears that banning those weapons did increase the number of assaults.

Excellent. It appears you've made some connection between the ability of members of society to have semiautomatic rifles and semiautomatic and pump-action shotguns (which I assume members of the USA are allowed to have) and the increase/decrease in the number of assaults in a society.

Can you direct me to any instances that have been reported in the USA news media in the last five years where owning semiautomatic rifles and semiautomatic and pump-action shotguns (as opposed to owning a handgun) have prevented assaults? I'm not even restricting it to preventing massacres; any simple assault will do.

Edited to change icon. I like consistency.