That is the std hole size.
I like 0.8mm when I can because I drill my own, but usually they are 0.8 - 1.0mm for std THT stuff.
An old 1/4W resistors have leads of 0.6 - 0.7mm, only the new cheap Chinese stuff has cost saving thin leads.
I don't think anyone does 0.4mm for actual THT components, so you would have to create a special small hole part if you want 0.4mm.