I set it by sight-ish. Not really scientific.
You can probably do a better job by measuring with calipers or something. I read the instructions that came with the die set and basically followed them. This was a few years ago, so here it is from memory...
You can look down into the die from the top and see the collet close around the neck. There is visible space between the collet leaves. I then dialed in the die a bit and visually inspected the crimp around the case mouth. I did this a few times until I saw a nice visible crimp groove all the way around the neck. After adjusting, there is still a little bit of space between the collet leaves in the die.
This is totally unscientific, but pressing on the bullet causes no set back. I haven't had any problems with them in the tube magazine.
I did crimp one all the way to check how it worked and it visually looked a little over crimped.
I use Berry's 150 grain plated with Unique or Trail Boss. I recently purchased a LEE mold that has a canalure built in, so I will switch to a roll crimp on those.