I think that the Second Amendment is still justisifed in my opinion, mainly due to logical reasons.
An example of logical reasoning, lets say that I own a store, I have a gun underneath the counter, someone comes in with a knife and demands my money and tells me not to call the cops, I pull that gun out and point it at him, chase him out of the store, and be able to call the cops, they look at the security footage, buglar arrested, no one is killed or hurt unless I start firing the gun and accidently hit the buglar.
An example of I didn't have the right, lets say that I own a store, I have a knife underneath the counter, someone comes in with a knife and demands my money and tells me not to call the cops, I take the knife out and try to start slashing at him, I get hurt and or killed, money gone, buglar is arrested due to the attack in the store and security footage identifies him. Yeah it got resolved, but at the cost of me, the innocent person, getting hurt or killed.