I'm going to try a wooden clothes pin to clamp around the neck while holding the bullet as straight as possible. - maybe even a little sanding on the neck portion of the Clothes pin. Jiggling the handle prior to the slow press seems to be pretty good. I have chamfered my once fired brass as well.
Went to the range with my ladder - 10/10.1/10.2/10.3/10.4/10.5 and 10.6 rounds -
All tumbled - all shot fine - no chrono but watching and feeling the recoil and ejection - I think 10.3 will be a target.
I loaded mags every other one with a factory for that quick compare and I'm OK with my choice.
The tumbling is a big concern - I may get the Lee FCD and see if I can resolve the issue - I thought heading up to 10.5 gr of H110 would do it. I weighted each one to make sure all was perfect.
Back to the bench -
RGRacing - TCM Ultra MS HC Combo