RICHMOND, Va. (AP) -- A former mine boss is asking a federal appeals court to toss out the conviction for his actions at the West Virginia mine where an explosion killed 29 workers in 2010.Gary May also wants the Richmond-based 4th U.S. Circuit Court of Appeals to immediately release him from prison. May pleaded guilty to conspiracy and has about four months remaining on his 21-month sentence.U.S. District Judge Irene Berger last month rejected May's claims that his trial lawyer was ineffective, had conflicts and made him a scapegoat for the Upper Big Branch mine disaster to protect Massey Energy executives. In papers filed with the appeals court, May continues to insist that he has been wrongly linked to the tragedy."May objects to the trial court's refusal to acknowledge the facts and the truth," the former mine superintendent wrote in his petition, which he prepared without an attorney's help.Prosecutors have not filed a response, and no hearing has been scheduled.May has said his defense attorney refused to let him testify that illegal advance warning of safety inspections was common practice at former Massey operations now owned by Virginia-based Alpha Natural Resources. He also says in his latest filing that some of his actions that were labeled illegal at his sentencing were actually legal and that he had no knowledge that the mine maintained two sets of inspection books - an accurate one for itself and a fake one to mislead inspectors.May wrote that his trial results "would have been different if the falsities and twisted facts were not repeatedly used against him by the Government and to argue for the maximum high end range for his sentence."