You can't, from a 223 Rem, you might get 3900 and change. 4400 fps isn't possible. You have to step up to a Swift or similar. He's quoting about the bullet from information that Hornady has published.
Safe Shooting!
Steve Redgwell
www.303british.comGet your facts first, then you can distort them as you please. - Mark Twain
Member - Professional Outdoor Media Association of Canada