SSK Brass 510 Whisper Unprimed 10/Bag (Special Order)

The .510 Whisper cartridge is a subsonic rifle cartridge developed by J D Jones of SSK Industries with a specific focus on subsonic use.

Despite the large bullet, this round is extremely quiet when used with a suppressor due to the subsonic nature of the cartridge. When used with a very high ballistic coefficient bullet, the round only loses about 100 ft/s (30 m/s) out to over 500 yd (460 m). This gives the bullet more downrange energy at that distance than traditional .30 calibre rounds such as the .308 Winchester and .300 Winchester Magnum. Sako TRG-S test rifles have achieved minute of angle, and better, accuracy with this cartridge at 600 yds.