ihmsa forums

is the whisper and the 300 black out interchangable?

Current thinking and recommendations are that it is ok to use a Whisper in a Blackout chamber but not ok to use a Blackout in a Whisper chamber. Its all about pressure and the lack of any real standards for the Whisper.

From what I have been able to gather. Brass - looks that way. Factory ammunition - what willk said.

A decent article on the two, if you haven't found it already.

http://www.americanrifleman.org/article ... s-of-gray/