Eley on the left, CCi on the right. Tight match chamber.

I have several styles of 22 LR reamers from standard SAAMI dimensions to some specifically for Eley with the EPS bullet. For sillouette rifles I prefer to use one that will engrave the first band of the bullet, and as stated it will make it slightly harder to close the bolt, this type of chamber is specifically set up to be used with high grade match ammo.
I also have several benchrest reamers with different lead angles. The one I prefer, and use more often, is the one that after inserting an EPS round in the chamber with my fingers, to where you feel it stop with no pressure, it will stick out .105"
Evelio.

That is exactly what that one does. You can see the rifling engraved into the first band all the way around on Eley. Anything that is kinda fat
like SV is a no go....

FWIW it shoots lights out with Eley. Incredible gun.