By combining the technologies of the GMX® and FTX® bullet design, the MonoFlex® bullet gives lever gun shooters another option. Constructed of a copper alloy, MonoFlex® bullets offer hunters a solid that won't separate, and when recovered, retains 95% of its original weight. Copper alloy differs from solid copper in that it is harder, tougher and does not foul or increase pressure the way solid copper bullets do.