I watched he videos. Thanks.
I did see punch presses. I have done a little work with punch press die frames.
Not much.
I've mostly worked with plastic injection molds.
Generally,a press has a couple of platens.The die frame rests on the platens
The die frame will have two (or more) plates the die components rest on...dead length.They usually have a head or shoulder on them. A retainer plate has pockets ,holes,and frames to fit over and retain the die components.
Nothing is threaded in with lock rings.Nothing is adjustable.Its just made right,to size,or its made over.
I didn;t see tooling detail enough to say for sure,but I did not see screw in dies,or lock rings,and I'd agree,probably no O-rings.
I did not develop or test the O-ring idea.FWIW Lee sells lock rings with O-ring grooves.
And this will take you to the book that recommended the technique of using the o-ring for straight and concentric handloads.
Bart,I don't know enough to argue the point.Maybe you could argue with the authors.
https://www.amazon.com/Precision-Sh...ks&sprefix=Precision+Shooting+,aps,252&sr=1-3
I just noticed from the date of the book ,1998,that I was pursuing handload accuracy at that level ,(which is pretty good ammo,not bench rest ammo)
23 years ago. Cataracts got bad.I couldn't see well enough to shoot good enough it made any difference. I try to pass on what I haven't forgot.
Its like buying audiophile grade stereo equiptment when I'm half deaf
I sold off my pair of Macintosh MC-240 tube stereo amps. They sounded better than I could hear.