This is a Sharps Bros. Stripped Lower Receiver known as the SBLR01 chambered in 223 Remington, model SBLR01.
The Hellbreaker's distinctive appearance is inspired by the P-40 Warhawk" which was one of the United States' most-produced fighter planes when World War II began.
Features:
Beveled Magazine Flare
Machined from 7075-T6 Aluminum
Oversized and Integral Trigger Guard