In my quest for self reliance, one category of things I've tried to acquire has been a variety of tools. On the top end are my mini-mill and mini-lathe. Tonight I used something a little further down the scale, a set of taps and dies. I have this inexpensive SAE and Metric set from Harbor Freight.
Yesterday when I shot my Pedersoli Brown Bess carbine for the first time, I wanted to use the ramrod for cleaning. One end has male M8-0.5 threads. However, I found that although I was able to thread on my worm, I could not thread on the adapter (part number SA-10-BESS) that allows me to use regular 10-32 rod tips, like a cleaning jag. So, I had to bring a separate range rod.
After work tonight I gathered up the ramrod, worm, and adapter and went out to my workshop. I first chased the threads in the coupler with an M5-0.8 tap and tried to thread it on the rod. No dice. Then I chased the threads on the rod itself with a die. That fixed the problem.
The total elapsed time was about ten minutes.
Think about how many threaded fasteners and parts you have in your life. A tap and die set may not get used frequently, but when threads on something get damaged, having such a set can allow you to fix it quickly.