I have Wilson, Dillon and JP Enterprize .223 case gauges, the Wilson and Dillon gauges do not check the case body diameter.
Below the full length resized .223 cases have been inserted backwards into the gauge, as you can see the cases drop further into the Wilson and Dillon gauges.
Meaning these gauges are a much larger inside diameter and do not check the cases body diameter, and only check cartridge headspace length.
I'm loading for three AR15 rifles and The JP Enterprise and Sheridan gauges both check body diameter. And if the resized case and loaded round drops freely into these gauges
cut with a finish chamber reamer they will fit in any .223/5.56 chamber.
The Dillon case gauges are made of stainless steel and better than a Wilson gauge "but" I use a Hornady cartridge case headspace gauge to check base to should length. And the finial "plop" test is into the JP Enterprise gauge. I taper crimp my blasting ammo and this gauge will also check for a neck bulge if any below the crimp.
NOTE, a fired case will not drop all the way into the JP Enterprise gauge and has the rim sticking well above the top of the gauge. The same case dropped all the way into my Wilson or Dillon Gauge and shows the case is longer than max headspace length. The only thing that will prevent a case from going all the way into these gauges would be a ding in the case rim.