In 2014, Sowery graduated to single-seaters, beginning with the MSV F3 Cup, where he took the title with ten race wins and fourteen podiums.

Later that year, Sowery partook in the MRF Challenge, in which he also claimed the title.

The following year, Sowery entered a few races MSA Formula with MBM Motorsport, where he finished fourteenth with eighty points.

There he claimed five victories and led the standings for a time before finishing third behind eventual champion Matheus Leist.

Sowery returned to the MRF Challenge in 2016-17 but only as a development driver working on future upgrades for the Championship.