30/221 (whisper) barrel length?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by eddybo, Feb 11, 2008.

  1. eddybo

    eddybo Well-Known Member

    Jan 5, 2007
    Not exactly a long range gun caliber but I decided to build a .30/221 (300 Whisper). I plan on shooting the 200+ class of bullets and understand that I need a 8 twist barrel to stabilize these as subsonic speeds? Since I am threading a supressor on the muzzle (assuming I get approved by the ATF) what would be a suitable barrel length? Can I get by with a 16 inch barrel or should I go longer?