Bulk Brass from Top Brass is 100% load-ready, guaranteed-once-fired brass that’s been fully reconditioned. It comes sorted, deprimed, full-length sized, reamed, cleaned and polished for your reloading needs. All rifle brass has received a case-mouth trim to ensure consistent length, while all military/commercial-mix reconditioned pistol brass is fully resized for consistent, uniform diameter on all shell casings. .300 Blackout is formed from once-fired military 5.56 NATO brass casings. Plus, Top Brass guarantees all reconditioned brass products are within SAAMI specifications for all calibers. Per 1,000.