300 AAC Blackout – 125 gr Sierra OTM – Black Hills (D300WHISPERN1) – 500 Rounds

Black Hills built its name on match ammunition, and its 300 Blackout supersonic load brings that accuracy to short barrel AR rifles. This listing is Black Hills 300 AAC Blackout 125 grain Sierra open tip match ammo, MPN D300WHISPERN1, sold as 500 rounds. It is a good fit for 300 BLK owners who want an accurate supersonic load for training, matches, and general field use.

Retail specifications list this load at 2,100 fps with 1,224 ft-lbs of muzzle energy. That is a supersonic load, not a subsonic one, so it will produce a sonic crack even when fired through a suppressor. The Sierra open tip match bullet is built for accuracy, with a small opening at the nose that results from the manufacturing process. It is a precision target bullet. It can fragment at close range, but it is not designed as a controlled expansion hunting bullet, so a dedicated hunting load is the better choice for deer.

This ammunition fits firearms chambered in 300 AAC Blackout, including AR-15 rifles and pistols with 300 BLK barrels, the SIG MCX, Ruger American Ranch, CMMG Mk4, and Q Honey Badger. A common question is whether 300 Blackout and 300 Whisper are the same. The 300 Whisper was the earlier wildcat that 300 AAC Blackout standardized, and Black Hills uses the Whisper name in its part number, but follow the marking on your barrel. Another common question is whether 300 BLK works with standard AR-15 magazines and bolts. Yes, only the barrel changes. Never chamber 300 BLK in a 223 or 5.56 rifle.

Black Hills D300WHISPERN1 is new production ammunition, not reloads, made in the USA in Rapid City, South Dakota. It uses reloadable boxer-primed brass cases and non-corrosive components. The 500 rounds come as 25 boxes of 20 from one lot, enough for serious training with match grade consistency from start to finish.