Would this Punch Set work for building / assembling of AR's?
Brass Punch Set
They're OK, but for working on an AR, which has a lot of roll pins, a roll pin punch set would be better.
Like this one:roll pin punch set
The Brownell’s roll pin punch set has more sizes and does not cost that much more.
The roll pin holder punches are like having a third arm, unfortunately they are rather pricey.
The brass punches are certainly nice to have.
these will last you a lifetime