The process of making Link’s slugs is so labor intensive and complicated that it is nothing short of being a true manufacturing process. It is not made by casting which is normally the way most of the lead shotgun slugs are made. TAOFLEDERMAUS You Tube channel has been testing these slugs in a couple of videos. Recently they’ve published a video, where the inventor (Jerry “Link” Linquist) of this slug shows how they are made. Watch that fascinating process in the video below.
As you can see, it is a pretty time-consuming process and requires equipment like a lathe, hydraulic presses and dies etc.
Here is the commercial video of the Link’s Slugs:
Below are the mentioned test fire videos of TAOFLEDERMAUS. If you watch this channel you might have already guessed that Jeff wouldn’t just test fire them without experimenting with the slug and modifying it to make it “more fun”. Particularly, he filled the cavity of the Link’s slug with magnesium shavings and black powder mixture and sealed the cavity with a primer to make sort of a DIY incendiary slug (no laws violated).
If you still want to make a slug like that yourself and you are ok with a simpler but similar design (without that copper band), you can probably find a set of dies at a company called Corbin Manufacturing. One of their slug designs is similar to Link’s slug but lacks the copper band.