Depending on the type of LedgeGrip™ you are purchasing it is important to know what type of receiver extension tube is on your rifle. This tube is also commonly referred to as the "buffer" tube.
Simply ordering the " larger" size unit will result in a poor fit.
Here are several ways to help identify which type of buffer tube you have on your rifle without having precision measurement tools. If you have a set of calipers you can skip to the bottom and just check the given dimensions. There are many manufacturers of buffer tubes, so understand there will always be odd exceptions to even these basic rules.
Several visual clues that you have a commercial buffer tube.
The end of the buffer tube may have a slight angle to it.
The adjustment holes on the bottom side of the tube may be spaced unevenly at the end on a commercial tube.
A properly installed MilSpec tube will measure close to 6-1/4" from the tube nut. A commercial tube may be a 1/2" or more longer.
If you a have micrometer or caliper, you can just measure and compare to these dimensions.
Finally, if you determine that you have a commercial buffer tube, this is a good dimension
to check. With your stock locked to the fully open position, our standard Upper Grip measures close to 3-5/16. Our Extended Upper Grip portion of the LedgeGrip measures close to 4". If you have any concerns, just contact us. We often make custom lengths for our customers at no additional charge.