This upper has it all for your Ruger MK IV. Not only is it extremely lightweight and well-balanced, but the accuracy is even better. How do we do that? We use a Type III hard anodized machined aluminum receiver to reduce the weight but then fit it with a stainless steel match barrel. Our Mamba LLV Competition Uppers are unlike other lightweight designs. Even though it is lightweight, it still features a stainless steel breech to withstand the rigors of competitive shooting.