I would shoot the donor as is, factory trim, to establish a baseline. If you are not satisfied, then do the K.

If I had a Hornet, I probably would go with the K because it takes headspacing away from the rim and puts it where it belongs, a shoulder.

But I don't have a Hornet because I have something way better -- a FIREBALL.


I'm waiting for MD to chime in here....

Up hills slow,
Down hills fast
Tonnage first and
Safety last.