The best way to check critical dimensions is with a Lyman case length/headspace gauge. The reloader simply inserts the case into the gauge to insure that it does not exceed the maximum or fall below the minimum allowable headspace. In addition, the gauge will identify a case which exceeds the maximum allowable case length.
Specifications:

Type	Case Length Gauge
Caliber	224 Valkyrie
Size
Quantity
Weight
Function
Compatible With
Material	Steel
Includes
Capacity
Media Capacity
Finish	Silver
Grain
Media Type
Micrometer Type