Check list for used firearm

[Klippermann]

Hi All
I hope this question hasn’t been covered before..
I am sure that a CGN member with good reputation and positive reviews will disclose any problems with a firearm they are selling.

What about private sales, estate sales or other sources of used firearms such as gun shows, pawn shops etc?
I am looking for suggestions or reference works for safety/function checks I can perform before buying (or firing)
i.e. Are machine screws mangled? Is action loose or wobbly? Rust? Signs of general abuse?
Should I have an older used gun checked by a gunsmith before use?
How much would a gunsmith check-up typically cost?

I know a lot depends on age and type of firearm but I am especially interested in pump or SxS 12 gauge for trap & water-fowl. Don’t mind older but don’t want to blow off any of my parts.

Appreciate your thoughts.
Thanks
K

[Stevebot-7]

There is no easy universal standard as some guns are designed quite different. Ie, AR15s and M14s and Mini14s and others can only activate the safety when the hammer is cocked. Others have safeties that can be activated independently of the hammer. I've seen people use guides that say "Make sure the safety is on before starting disassembly." and thinking that their AR15 is broken because they can't get the safety to activate.

These days the best bet is to google the make and model and dissassembly or function check videos on an individual basis.

[Klippermann]

Thank you Stevebot-7 but I was asking a more general question not "safety function" but rather "safety and function" of firearms esp shotguns.
In other words I am not only interested in whether the safety mechanism functions but rather other common safety issues in used guns not sold by reputable members such as found here.
For example I read descriptions such as "locks up tight" and am asking what is tight? Paper test?

Is there a reference work recommended rather than searching high and low on the internet?
And again, what kind of checks would a gunsmith perform and about how much might that cost.

Thanks

[Stevebot-7]

That's going to be very individual. Especially with older firearms where each one might have been hand fitted rather than CNC produced. What is tight for one gun might be loose for another. What is safe for one might be dangerously out of spec for another.