Sig Sauer cases are made from American, premium brass. These casing are rigorously tested to ensure unparalleled durability and dependability, each casing undergoes rigorous in-line and postproduction quality assurance testing to ensure a flawless casing. This is not loaded ammunition.
Brass Preparation: With bulk rifle brass you may sometimes notice a few case mouths are “out of round” or slightly dented below the shoulder. These imperfections occur in the final tumbling wash operation after the case mouth has been annealed. Brass manufacturers are aware of the case cosmetics and have worked to mitigate it, but due to equipment design, denting may still occur. Minor dents are normally removed in the first firing and will not affect case life or performance. On non-plated brass, you may also notice all the anneal stain might not be polished off, which may give the case neck a pinkish color. With some smaller caliber cases you may notice the case mouths to be slightly belled.
With all new rifle brass, you should first straighten out the case and case mouth, then chamfer and debur the case mouth inside and out. To straighten the case mouth, run the case part way into the sizer die and let the expander ball straighten the brass. To prevent the case neck from stretching, be sure to lubricate the case neck inside the case mouth.