Ratshooter!
In theory, you should be able to shoot a plain base cast bullet at 2200fps without leading, but in practice, its not likely. C.E. Harris wrote an article about doing just this in .30 caliber military rifles using a paper-patched bullet. He got good accuracy and performance using wheel weight alloy, but his method was really involved and took a lot of experimenting.
Cast bullets (even really hard linotype alloy BHN30) are much softer than jacketed bullets (BHN100) To get velocities over 2000fps requires more pressure than the lead alloy can stand. Once the alloy's strength is exceeded the bullet slumps, and usually not uniformly. Even if you don't get barrel leading, accuracy will be non-existant. Gas checks help the cast bullet base to resist both gas cutting (that causes most leading) and severe deformation under pressure. They allow lead alloy bullets to be driven at faster velocities (and higher pressure) than plain base bullets.
You should get a copy of Veral Smith's book "Jacketed bullet performance from cast bullets". You can find information about Smith and his book on GBO. Smith (Lead Bullet Technology) makes bullet moulds cut to match your rifle's throat that are the correct design for high velocity/pressure loads. He also markets bullet lubes that help make this possible
