Basic HK Toggle Question

[LugerVern]

I thought I knew the answer to this but maybe not: So help please.

Are HK toggles back bored all the way or part of the way or does this vary through the years?

Attached is a picture from the toggle of a 1942 HK and clearly shows a partial back bore, but I know I have seen toggles bored all the way through on some guns-- is there a right and wrong way?

thanks

Vern