The Precision Frame Lug

If you own a factory Ruger® MK IV™ or one featuring an aftermarket upper, such as our Mamba LLV upper, you may have noticed over time that the frame-to-upper fit isn't as tight as it once was. This issue comes from minor variances on the frame lug.

It only takes a slight variance to create a noticeable issue.

In a few cases, we have seen these tolerances vary enough that they have caused damage to the upper.

Manufacturing aftermarket parts is one of our most challenging tasks.

We are working with tolerances out of our control.

Our job is to figure out how to eliminate those variables, providing you with the best product once your build is completed.

Our new Precision Frame Lug is the perfect fix.

It is machined from 416 SS, heat-treated, and black-nitride coated for ultimate durability.

Order yours today!