Iron sights are fine. I shoot a lot of CAS so I am used to shooting fast and hitting with iron sights. The advantage of a scope is that you not only see your target, you see what is in front of it. Mainly grass and brush. Scopes allow you to shoot through brush better especially with these light, fast bullets we shoot.
Up to a hundred yards, I have a .357 with a tang sight that I could nail anything with. I prefer to shoot a scoped .223 just so there are no excuses.
Pack