CBI 6 CM Match chamber ?

[Shooter0302]

Anyone running a CBI 6 CM "Match" chamber ? I have a question about where the full Dia.[.243] base is when you seat 105 th 115 gn bullets to on or at the lands ?

[Texas10]

If you're seeing too much of the bullet in the case at your touch dimension, use a throating reamer to lengthen the throat to fit. Or you can take a dummy round (bullet seated optimally) and the barrel to a smith and have him throat it for you.

Does this help answer your question?

[Shooter0302]

If you're seeing too much of the bullet in the case at your touch dimension, use a throating reamer to lengthen the throat to fit. Or you can take a dummy round (bullet seated optimally) and the barrel to a smith and have him throat it for you.

Does this help answer your question?


Not really, and here's why, ask CBI a simple question , what is the total length from the case mouth to where a bullet will touch the lands ? To avoid giving a simple answer they send reamer diagrams. The TOTAL from the diagrams is .383" for the match, and .233" for the "standard".
It seams that when asking the same question to Bbl. sellers or makers they usually use the term "freebore", in the case of the CBI Match chamber I was told the freebore was .183". some how they ship the .200" referred to as LEAD.
When I had my 22 BR chambered I took the bullet with the longest bearing surface, seated that bullet so the gas ring of the bullet was at the neck body junction, and had the chamber cut so that bullet would touch the lands, knowing that with the long neck on the BR case I could seat other bullets not as deep and still be at the lands.
Not the case with the 6 CM case necks length. BUT with my 75 year old eyes and age related stuff, it probably doesn't matter