This set of parallel punches is unique in that the shaft slides along the length of the punch, so only a minimal amount of small diameter punch is unsupported that limits the likelihood of bending or breaking punches like SD mentioned. The Brownells set is useful sometimes, but as in this retaining pin situation, the shaft diameter was too large to fit in the narrow confines of the bolt access.
For starting and finishing some pins where a tapered "starter" punch can not be used for whatever reason, I made a set of short shaft punches and hardened the tips which avoids bending and breakage.