Mausers will do that- I have a K98 that blows back into your face at light loads, "light" being something like 70% of the max load. I forgot why I was trying light light loads like that once but I did and saw it happen. The blowback stopped at about 80-85% of the published max load when pressures got high enough to expand the case and seal properly.
Isn't a big part of what makes a Mauser, a Mauser action, the chamber pressure relief flow path through the bolt and out the bottom (and thence everywhere including your face)?