How Much O-ring Squash?

[Ronno6]

I will be inserting a 1/16" CS O-ring into the rear of the barrel port of the breech block of Crosman 2100 pumper.
In order to get the transfer port in the barrel lined up with that in the block I will need to remove a bit of barrel.
Question is: how much material do I need to remove and how much should the O-ring be compressed?
.010" compression ??
.020" ??
I don't envision a lot of pressure or volume of leakage around the barrel inside the block, but there is some.....
That O-ring may also provide some better sealing around the bolt probe.
I will also be adding an O-ring at the front to be held in place by a set screw collar that will also serve to center the end of shroud on the barrel.....

[mikeyb]

https://www.globaloring.com/o-ring-groove-design/

[Ronno6]

Thanks, mikeyb.

Looks like 25% about compression or .01525" for the oo8 O-ring (.07" CS)
This application may not require that much, but is no problem to try.