Interpreting carbon deposits on case necks to help determine neck thickness

[louielouie]

If a bullet will not slip into the neck of a fired unsized case then the neck to chamber fit is to tight. Turn off another .0005 reload fire and re check

Well, even the Norma 130 (ever-so-slightly smaller in OD) won't go back into a fired case. The first firing was with jammed bullets to make sure case was fully supported when it expanded. I should probably do a chamber cast before I go any further since I don't know what the reamer was spec'd to.
I really appreciate everyone's comments to the O.P. and to me - 'tanx. FWIW, 51.4gr RL-22 with a Wolf LR behind Hornady 140 BTHP jammed 0.020 was a really nice way to start out.