[E-Revonut]

Rosin core solder works fine, no flux needed its already there. Heat up the wire with the iron till the solder will melt by touching it to the wire. Then get the bullet hotter than hell! I use a small butane lighter to help get the bullets up to temp then fill them with solder, heat the wire/solder up again a little and then stick it in. Another important step is to keep it all still while the solder cools and hardens. 6.5mm bullets are just a pita imo, however doing it like this I have never had a bad connection or had one come apart.