If the rifle wont pass the bump test then the adjustment is not safe... I do not know if there is anything you can do to get a more "positive" engagement on the sear... If you decide to still use the rifle while it is set up like this make sure the gun is pointed in the target direction and only close the bolt when you are ready to fire. If the gun stays operating as it is you should not have a problem but you never know when some other factor (weather, gun wear/tear) is going to change this from failing a bump test to fail when closing the bolt. Be very careful, weight your options and good luck.