For gunsmithing get one of Brownells Magnabit sets, it is the way to go. I bought mine 36 years ago and and have used it hard. They have a number of specialty bit you can buy to augment the main set. I used mine every day for for five year when I was full time gunsmithing and continue use to this day doing custom and personal gunsmithing.
https://www.brownells.com/gunsmith-...a-tip-sets/magna-tip-super-sets--prod417.aspx
https://www.brownells.com/gunsmith-...a-tip-sets/magna-tip-super-sets--prod417.aspx