I'm gonna beg you not to fire those sticky chambering brass till you know for sure it's just a shoulder dimension thats a hair long. Odds are it is but even a 5% chance that something is pinching on the bullet or neck of the brass could make for some bad high pressure. It isn't worth it. Park those shells till you get the gauge and can check it out.
I just bought some once fired brass to use in a tight chambered 270 win that I own. It was too cheap to pass up and I found out with the gauge that the brass was fired in two different guns. Some had the shoulders blown forward .002 more than my chamber and some was blown out .007. Long story short....I could use my normal die setting to chamber the shorter stuff but had to crank the die in a bit to make the .007 chamber in my gun. I might not buy any more brass like that for that particular gun.
Something thats been working good for me is I set my dies to work with at least one of my guns for a shoulder pushback of about .002. Then I put a mark on the threads of the sizing die right above the set screw on the lock ring. If I'm loading for another gun....maybe a buddies....and I need to adjust I find that moving the marks about 1/4" apart will make a change of about .004" on the shoulder. Also if you ever get into annealing you'll find that the brass softens up to the point that you will most likely need to make a die adjustment.
