Well , even if my personal 2 cents might be off topic :
Over the last few decates , I more then once purchased an antique pistol or rifle at auctions that , after exam with my bore scope , turned out as being loaded !
I honestly must say , that in my early years , I clamped them in my bench vise and fired them from outdoors with a string and ALL of them went BOOOOOMM .
Today , I wouldn't practice that any more , since I don't know , if a brainless has packed some unknown/unmentionable behind the ball .
When a new item enters my collection today , I ALWAYS try to unscrew the plug and look for the shape of the then visible , entire barrel , which is , in my opinion , much more secure than ANY bore scope .
Anyway : even a gun , which has been loaded with BP for over 170 years , still can fire its original load !
So be aware !