Changing OAL on Bonanza Co-Ax

[metalcaster2]

When seating 175 NOS CC bullets I am getting up to .010 OAL differences. Cases are all trimmed to length and sized using a forster sizer with neck bushing. Haven't had this issue with 168 MK's. Is the seating stem to tight for the bullet profile? Any help would be appreciated. Thanks.

 

[BirdEyes]

Re: Changing OAL on Bonanza Co-Ax

This tells me that your problem is not really with the 185 gr NOS but with the 168 MKs. There are bullet length differences particularly with the SMKs consistent with the dimension you referenced for the NOSs. Seating should be done to the ogive of the bullet, not the tip for consistency and repeatability. This means you need to make allowance for bullet variances when seating to magazine length if that is a consideration. It appears that your seating die is pushing on the tip of the SMKs if you really are getting consistent measurements for OAL. Your seater on the NOSs would seem to be seating more to an ogive length since you are seeing some variation in OAL.