it's comon not normal. i've had a fair share of bank vault feeling lockback from fallkniven, fontenille pataud, fantoni and other more traditional makers, but the action on those is always stiffer, like tighter overall tolerances and a waaayy stronger backspring.
now you have to choose what you want, a one end opener that can have some sensible play if the it's on the loose side of the tolerances or a solid knife that'll kill your thumb. you won't get the best of both worlds with g10 and vg10 for 120$. the bolstered fallkniven are 200+, the fontenille is almost 200 with rwl34 upgrade, the fantonis are 200... you probably got lucky on your pika
it's a sad world isn't it ?