The powder should be burned up and the bullet stabilized in a 20 inch barrel. If the deal is to good to pass up Don't. What will you be shooting with it? If your shooting coyotes I wouldn't be too concerned about long range with a .204 cause with a .204 I wouldn't shoot them much over 200 to 300 yds.Of course there are some that will disagree so this is just my opinion. Good luck in whatever you decide.