While there are a limited number of possible combinations, I have never heard of or personally seen someone crack an unknown combination even using this list. Not saying it's not possible, I just haven't seen it myself.
That is one concern that led to a deadbolt/backup key option on these.
I have that pictured safe less the key and its awesome. It pops up with a liftgate piston presenting the gun.
Mike
Sent from my cell phone with a tiny keyboard and large thumbs...