Starting with .22LR and rolling through some seriously larger calibers (.50 BMG, anyone?), a fire resistant safe just can’t hold up to a firearm.
As Matt and company found out, larger calibers such as .500 Magnum and .45-70 gave impressive penetration– even when it came to blasting through the steel bars and hinges holding the door on the body.
You don’t even want to see what a .338 Lapua Magnum does at close range.
Sure, these types of safes are UL Classified to survive in a fire for a bit, and resist some pry and burglary attempts, but just keep in mind these aren’t meant to stand up against gunfire. And (safety warning) you should never shoot a solid object with a firearm due to ricochet potential so don’t try this at home.