new whisper ammo from Hornady

[Spook]

Originally Posted by rsilvers

Not all Whisper(R) brass interchanges. No one really knows if Whisper brass is supposed to be 1.355 or 1.4 in length. People have seen drawings for it both ways. There are at least three different chambers called 300 Whisper. 300 AAC BLACKOUT is the standard for 300-221 type cartridges now, and there is just one drawing for it.

The Hornady is made to be within 300 AAC BLACKOUT specs.

...or the blackout was designed to fit in a whisper chamber.