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View Full Version : Checking Freebore, Cerrosafe?



fireball
03-25-2009, 05:06 PM
Greetings All, could use a bit of input here I bought a new never fired Pac-nor barrel in 6BR with new lapua brass, from a member of our club for my savage low profile. The barrel is 1 in 12 twist, .272 nk lapua-norma chamber. I did a chamber-bore cast with cerrosafe, can I determine the freebore with this cast? I can clearly see where the lands end. would it be where the lands end and neck starts? Barrel is not installed and may be some time as I need dies ect. Thanks Jay

Jay, Idaho
03-25-2009, 06:05 PM
Yes, it is the area between where the neck ends and the rifling begins. It should be smooth all around and mic about .242-.243 diameter or so. You could also mic the neck area and see what it really is, not what it was supposed to be.
If it is a 1:12" twist, it probably doesn't have much freebore since it will be shooting lighter bullets.
Why do you need the freebore length to order dies?

Jay, Idaho

fireball
03-25-2009, 07:42 PM
Hi Jay, No don't need it for dies. Just checking things out so I don't have any surprises like you mentioned;) neck looks good at .2724 thats at 2 hours after the cast, I have to dig my calipers out but looks like freebore would be .060 eyeing it up with the mic, it has some wrinkles right there and hard to see, I'll pour one more a bit faster and see if thats gets rid of them. Thanks Jay

Donald
03-25-2009, 10:10 PM
You should still be able to shoot 65 grain bullets with the .060 freebore. With a 12 twist my 6br seems to like 80 grain bullets best. Don't know if it will stabalize anything longer.