Just as a FYI... most cellofone tape is .0015 to .002 thick...

So if you take a piece of tape and put it on the base of a factory round... trim the edges with an exacto knife, then chamber it...
Put on a second piece, now you are around .004...
The third gets you to almost 6 thousands... and so on..

Measure your tape thickness before you do it and you know where it is with this trick.

At some point it’s going to bind.. and that’s when you hit your headspace limit