Go to your local hobby shop and buy one length of Model Airplane landing gear spring steel wire. It comes in an assortment of diameters. IIRC, there is one available that is somewhere around 0.052". Cut a two inch long section with your Dremel tool and make sure the end is ground perfectly square to the world. That becomes your drift punch for the 0.055" cross pin in the front sight. The rest of the landing gear wire becomes one of the most useful tools you will have in assembly of firearms. I sharpen one end to a fine point and leave the other end flat ground but I bevel the edge just slightly so that it won't scratch blued surfaces. I use it to guide parts into place, align holes in parts, pry apart parts, scratch hardened deposits out of 90 deg. corners and a bunch of other uses that I can't recall right now. ......
BTW, there is also a heavier landing gear wire that is 0.063" dia. that is even more handy on the workbench. Buy one of those too. ....