30 degree cutter on 40 degree shoulder?

[Lucky6547]

Hello,
I have a Pumpkin turner for my 6.5x47, and I believe the cutter is for 30 degree shoulders...if I were to get the 7mm mandrel and attempt to turn necks on a 280ai with a 40 degree shoulder, would I run into any issues?
Thanks,
Ken

 

[Steve Blair]

Yes. You need a cutter in the 40 to 45 degree range.

 

[Lucky6547]

Thanks!
Would there be any issue turning necks on a 308, with it's shoulder being less than 30 degrees with a 30 degree cutter?
Thanks again,
Ken

 

[Steve Blair]

.308 has a 20 degree shoulder. A 23 degree cutter (.223) would be a better fit.

 

[Lucky6547]

Thanks for the info Randy!
What about with the 308? Less of an issue?
Thanks again,
Ken

 

[Steve Blair]

The cutter should be 2°-5° sharper than the shoulder. A 30° cutter would work Ok on a 20° shoulder but would take a fairly narrow cut when reaching the shoulder. What you want to avoid is what Randy described or a situation where the cutter angle exactly matches the shoulder angle. The latter causes the cutter to take a large, full width cut and that is not what you want.

 

[Lucky6547]

Thanks for explaining it more clearly for me,
Ken