[What's_nitro?]

Use your 100W iron. Always tin the wires first- get about 1/4" of the wire full of solder. For bullets, I heat them up and fill them about 1/2 way with solder then stick the tinned wire into the pool of solder. Keep the iron on it for a few seconds to melt the tinned wire and make a good connection. Pretty much the same thing you do, but the tinned wire makes the difference between a good connection and what's called a "cold joint" that falls apart. The 60/40 rosin core solder works fine. IMO using separate flux is unnecessary. If you don't have one already get one of those "helping hands" things with the alligator clips to hold parts while you solder them. You can actually hold the wire in one clip, the bullet in another, and move the arms so that the wire is already inside the cup of the bullet. Then just heat it up (a lot) and fill it with solder.