I have just chambered my .308 with a reamer recomended by PTG speficially for the 155.5g Berger fullbore bullets it has a .336 neck and 0.060 freebore.
With this setup and the bullet touching the rifling there is ony 0.150" of the bullet engaged in the case is this OK?
Also Berger suggest a large jump might work well http://02b0516.netsolhost.com/blog1/?p=43
When using this approach to test seating depth do you change the powder charge to try and keep the velocity and pressure constant? It looks like the chamber pressure can change by up 6K psi and the velocity by about 100fps with a 0.130" seating depth change if you were using RL15 then this is about a 1.5g change in powder charge. If you do not do this then it would seem to me that there are too many variables to come to any conclusion??
Thanks Jon
With this setup and the bullet touching the rifling there is ony 0.150" of the bullet engaged in the case is this OK?
Also Berger suggest a large jump might work well http://02b0516.netsolhost.com/blog1/?p=43
When using this approach to test seating depth do you change the powder charge to try and keep the velocity and pressure constant? It looks like the chamber pressure can change by up 6K psi and the velocity by about 100fps with a 0.130" seating depth change if you were using RL15 then this is about a 1.5g change in powder charge. If you do not do this then it would seem to me that there are too many variables to come to any conclusion??
Thanks Jon
