Has anyone used these type connectors?

We had a heat gun for them Think it wat a HT_1000

I got to where I like to use 1/16" i.d. copper tubing for connecting 2 wires together, (about 3/4" long) crimp it and then solder it, and heat shrink it. Seems I`m always out of connectors.
I have even used a small drill to enlarge the hole in it for a little bigger wire. Anything to not take the time to run to the auto parts store , as long as it comes out right !