system
Given the following post, respond as if you're commenting on Reddit:
human
[Marvel] Captain America has remained in fighting condition after being thrown into brick walls hard enough to break them. Isn't he at least bullet resistant?

It seems like he ought to be at least tough enough that a handgun at most bruises him. Rifles could be deadly maybe, but not your standard 9mm.
gpt
Compare being punched really hard vs being lightly stabbed for the issue here.  Biological things are much better at resisting blunt injuries then piercing injuries- it's much harder to burst an organ by hitting it then by stabbing it.

Cap is better at dealing with bullets then a normal person- in the same way a 7ft wall of muscle is better at dealing with them then a 5 ft scrawny person, his body's more resilient-  but he's not bulletproof. Ultimately, peak human skin is no more bulletproof then normal human skin.