Normal enough.
If it doesn't close on your hand from steady spine pressure applied by hand, the lock is fine.
If it bugs you down the road, just use your thumbs to press the lock-bar over further to increase spring tension (bend it when the knife is disassembled, that is).
Also, make sure when closing the knife that you get the lock-bar out of the blade path entirely before closing it.
I've seen where people scrape the lock-face when closing by pressing on the spine of the knife
as they close it, basically making premature lock wear.
If the lock-up is at 50% like the pictures seemed to show, it has plenty of life in it.