SWThomas, I also have a Dillon. It is VERY wind and breeze, BREATHING sensitive!!! I have a love hate relationship with it. lol.
With that said... it is great for weight sorting primers and bullets fast! My RCBS 10/10 and 505 scales were both off by 1/10 th gr each. I borrowed a friends scale, with my Dillon, decided on .204 cal 40gr sorted bullets. from there, I counter drilled the existing holes in my 505 scale until it matched the other 4 scales. Basically, tweaking the counter weight by 1/10th gr. Now, my 10/10 and 505 RCBS scales are dead on without sending them out for tweaking. Just be careful how much material you remove. If to much is removed, you need to add lead shot to your cup holder to "balance" the beam once again. (the aluminum cup below the brass powder pan has lead shot in there to "balance the scale" just remove the philips screw and you'll see what I'm talking about)
When weighing my charges, I "Blow" on the cup. This gently moves the powder cup to truely balance the powder charge. And If I don't....guess what.....1gr off! So, gently blow on the cup, not enough to blow powder out of the brass cup, but enough to move the actuator arm. This allows the magnets to do their work to equalize the beam to zero if the charge is perfect.
I'm adding pics to show how I tweaked my scale a bit. I used a Smith Knife Sharpener(diamond cut) to bring the balance knifes on the beam to a sharp point! You must clean DUST out of the Quartz crystals and keep the beam posts SHARP! Otherwise, false readings every time. Make sure your beam is straight and the copper coated steel is perfectly centered between the magnets. Adjust as necessary. I have adjusted and tweaked USA and Mexico made scales. If they are tweaked right and cared for properly, will serve you great for years to come.
EDIT: my friend with the scales had a 50 gr weight to zero the scales with.