The Fifth Circuit has determined that 8 USC § 1227(a)(2)(C), which defines the firearms deportability ground, does not encompass offenses involving the transportation of firearms. As such, the petitioner, who had been convicted of transporting a firearm in Oklahoma, remained eligible for cancellation of removal for non-lawful permanent residents.
The full text of Flores Abarca v. Barr can be found here:
http://www.ca5.uscourts.gov/opinions/pub/17/17-60236-CV0.pdf