reamer dimensions

[mrmarmota]

When reviewing dimensions on a reamer print ,how does the average guy know what is the correct free bore ?There are so many variations on the same thing .
Is there a rule of thumb for correct free bore for a particular bullet caliber, weight, length, and style?

 

[Alex Wheeler]

The best way is to send in a dummy round how you want it for the reamer grinder to measure.

 

[fguffey]

what is the correct free bore ?

I have 65 chamber reamers, I have access to 200+. It is not easy to shorten the free bore, it is possible to increase free bore. Those that choose to increase the free bore have their reasons. One comes to mind, an owner of a rifle with a 300 Win mag chamber decided to improve the performance so he increased the length of the neck and free bore. Moving the bullet out of the case increased the case capacity and increasing the free bore prevented him from seating into the lands.

F. Guffey