seating bullet = large bulge below shoulder

I always feel stupid asking your pros for help, but I gotta learn somehow...

I have reloaded 9mm, .223, .22-250 and everything has gone bang just fine.

Fast forward to my first attempt at reloading .308

Using Lee dies and my foster co-ax, I made 20 rounds. All brass (once fired FGMM) was trimmed to a uniform length. I was using 175 SMK. I adjusted the dies per lee instructions.

10 looked great (and shot well). 10 looked bad, and wouldn't chamber.

The 10 that wouldn't chamber had a narrow but very protruding bulge below the shoulder.

It is odd to me that with uniform brass, the same dies and the same press I made 10 good rounds and 10 bad ones.

Could it be the case mouths are too tight? The 175 gr. SMK are uniform in diameter. I have seated the 175 SMK to the same OAL as my FGMM.

I have Forster seating dies for my other calibers, maybe I just don't how to setup lee seater dies?

thanks in advance for any help!
Jim


 
Re: seating bullet = large bulge below shoulder

You probably had the seating die body turned down too far and the crimping step was collapsing the shoulder down, bulging it to a degree. Usually, this will happen on the longer ones, as the step will perform the crimp up until a certain point.

Unscrew the die body a turn or two, readjust the seater stem and crimp in a separate step if you have to crimp.

Chris