Science educators and researchers have bemoaned the lack of reform-based science in elementary schools and focused on teachers' difficulties (i.e., lack of knowledge, interest, experience) in enacting quality science pedagogy. We present compelling evidence that challenges assumptions about science education reform and draw on a practice theory perspective to examine the stories, commitments and identities of thirteen teachers, whose beliefs and practices aligned with those promoted by science education reform documents. Through ethnographic interviews, we learned about these teachers' critical science experiences, perceived science teacher identities, and their goals and commitments. Their stories highlight institutional and sociohistorical difficulties of enacting reform-based science, the many biases, contradictions, and unintended consequences prevalent in educational policy and practice today, and emphasize how easily the status quo can get reproduced. These teachers had to work as "tempered radicals", "working the system" to teach in ways that were consistent with reform-based science. (Contains 1 table.)