What must be done after any trimming operation on brass?

After trimming brass, deburring both the inside and outside of the neck is essential. This process involves removing any sharp edges or metal shavings that may have been created during the trimming. If these burrs are not removed, they can lead to improper seating of the bullet or cause damage to the bullet itself during the loading process. Deburring enhances the consistency and reliability of the brass, ensuring better performance when the ammunition is fired.

While other options, such as coating with lubricant or weighing trimmed cases, might be relevant in specific contexts, they do not address the immediate need for ensuring smooth and reliable handling of the brass after trimming. Testing for uniformity is important but follows after the initial preparation steps, including deburring, to ensure proper function and safety in reloading.