Keltec PR57 vs. SW 351 PD vs. Brownell 180 vs. BRN 180: A Comparison Among several get more info periods, enthusiasts ’ve explored unusual personal defense weapons , and some emerge as particularly worthy choices . This article contrasts four noteworthy models: the Keltec PR57, the Springfield Armory SW 351 PD, the Brownell 180, and the BRN 180.