You're setting it up perfectly. The reason your measurements show .003-.004 is because there's never a perfect match between the shoulder angle in your chamber and your FL sizer and the datum on your comparator.
More references towards a # being a "gas gun" number only go to show the level of...
For the lurkers or readers.... regarding the "problems" folks are having regarding pressure with Alpha GT...it's likely a FL sizing die base dimension issue.
Measure at the ".200" line, if you put a case on your bench, .200 up from the case head, measure the diameter of a virgin, fired...
You need a mentor more than anything right now it sounds.
You can go it your own, but folks that seek out an in person mentor, that has accomplished your shooting goals, and is an active shooter will save themselves $$$ and money.
Is there a competition you can attend in your intended...
It's not a hard puzzle to solve. It is frustrating. Think of all the 6XC Gen 1 vs Gen 2 vs 6-22/250 drama that's out there.
If you don't know how, ask your smith. Or PM me. I've read your other posts, you seem very knowledgeable, and obviously can shoot.
The Reamer->Virgin brass-->Sizing Die...
Your cleaning methods, fire string intensity (tempo & # of rounds), the lot of steel in your specific barrel, will be far more influential factors in your barrels lifespan in terms of potential competitive precision capability.
Hornady brass. Blem RDFs. Piercing primers. Compressed loads. Action screw torque. Two different powders. Two different primers. No seating depth test. 170 rounds. And it’s supposed to shoot like 32.5 of Varget in a Dasher shooting 105s?
How about try the known Varget loads in Alpha brass with...
This is an excellent post for those looking to travel with their weapon to read and reread.
Do you care more about your itinerary? Use TSA locks.
Do you care more about the security of your weapon/gear? Use your own locks.
I agree, right tool for the job ?
Offering a cross disciplinary example for perspective, to demonstrate that stage cof isn't out of the realm skills wise.
Service Rifle High Power shooters shoot clean 20 round strings at 200 yards (7" 10 ring) with 2 sighters.
A 10" plate at 300 substends that same target size to 300 yards.
Sounds like a stage with a competitive opportunity if everyone was bombing it.
Have you considered imposing a transaction "Tax" those not complying with your intent for the PX, using # of transactions and frequency as your filters for when your "Tax" kicks in.