Thanks for all the help and advice everyone, I'll try and answer any questions all in one post:
I did make 2 dummy rounds, and just made another to confirm nothing changed. They headspace in the barrel just like the second example in steve4102's post.
I just made another dummy at 1.160" oal, and it also feeds and headspaces fine.
I measured the mushroomed diameter of the primers, and they are .179", so just a few thou bigger than a new one.
The bullets are moly coated, so no lube. They measured at .356" with my caliper.
My scale (Dillon eliminator) should be good. When I bought it, I checked it against my brother's two scales and all weighed the same.
The powder is regular clays, not universal.
I may try a different primer and at the longer OAL. These are the only pistol primers I have now, but can pick up something different later.