, this node is not about dope
A sight pusher is a specialized precision adjustment tool that is used to slide iron sights on pistols and rifles to adjust the aim to make it correspond to the point of impact of the particular gun and load combination.
The kind of load you use, which is the combination of bullet type, bullet weight, bullet material, and charge type and weight is less a factor in handguns than in rifles.
A sight pusher is very handy when replacing your three dot combat handgun sights with perhaps a tritium filled night sight or simply to readjust to zero your firearm.
In a pinch you can make a crude field expedient of a sight pusher using spent brass cases and a heavy enough rock. The brass should be hard enough to transmit the force of a blow from the rock but will also be soft enough not to damage any steel sights.