- The Mama Bear by Bond Arms has a compact 2.5" barrel chambered for powerful .357 Magnum or .38 Special rounds. This derringer has a stainless steel double barrel and frame with a crossbolt safety, automatic spent casing extractor, and a patented rebounding hammer. Its spring-loaded cammed locking lever allows for a tighter barrel/frame fit and rapid loading and unloading. It is compatible with all Bond Arms interchangeable barrels. The Mama Bear has a blade front sight, fixed rear sight, and pink wood grips.