House Oversight and Government Accountability Committee Chairman James Comer is threatening to investigate the Secret Service over a 2018 incident involving Hunter Biden’s purchase and alleged mishandling of a firearm.Biden purchased a handgun in 2018 from a Delaware gun dealer. His former sister-in-law and then-girlfriend Hallie Biden reportedly threw it away out of concern that he would use it to harm himself. Federal officials are considering charging Biden for allegedly lying about his drug use in a background check form submitted to the Bureau of Alcohol, Tobacco, and Firearms.“There are numerous instances where the …