BoilerUP.....I posted this about 3 months ago, this may help you. This is for a CBI 6mmBR 8T barrel.

If anyone sees something that doesn't seem right, jump in and let me know.

Using a Hornady Lock-n-Load OAL gauge I got these results.

Berger 105VLD 2.427"
Sierra 107 2.390"
A-Max 105 2.324"
A-max 87 2.262"
A-Max 75 2.203"

I am using NEW paper box Lapua brass that the OAL is 1.556". Using the above measurements this would mean that:

A-Max 105 had .456" in the case (bullet lenght 1.224" )
Sierra 107 had .401" in the case (bullet lenght 1.235")
Berger 105VLD had .363" in the case (bullet lenght 1.234")
A-Max 87 had .334" in the case (bullet lenght 1.040")
A-Max 75 had .290 in the case (bullet lenght .937")

Using a Sinclair chamber length gauge it measured 1.578" and the measurement to the lands with a Berger 105VLD was 1.668"
To the lands= 1.668"
Chamber lenght= 1.578"
Freebore = .090

Since I took the above measurement I have talked to Jim Briggs and he said the free bore according to the reamer CBI is using should measure at .093"

Old paper box Lapua brass has the shoulder .003" farther forward then the new Blue box I have. Measurement to shoulder 1.068" old brass / 1.065" new brass. Which leaves the new Blue box brass .003 shorter in OAL then the old brass. This was measured in a Hornady head space gauge using Sinclair SS inserts. OAL old 1.556 OAL new Blue box .1553