This 5" long Marlin lever action scope mount receiver rail works with the Costa Marlin M-LOK Handguard + Modular Rail System.
Why a Three Rail Arrangement?
The Costa Ludus/Ranger Point Handguard + Rail System was designed to provide lever gun shooters with exceptional flexibility in setup and cost while safeguarding the qualities of handling and accuracy that we love about these fine firearms. In order to meet all these goals we split the top picatinny rail into 3 separate sections. The handguard can be used with all 3 picatinny top rails, none, or any combination of two. It’s worth noting that installing one or more Gator rails makes the handguard even stronger.
In order to accommodate a range of manufacturing tolerances in the host rifles, we have imbued the entire handguard/rail system with adjustable fitments. It’s important to understand that when we talk about manufacturing tolerances we are talking about a universal phenomenon. As an example, there is really no such thing as a straight barrel. Each OEM must decide for themselves how much curvature is acceptable, and it is pretty well understood that a noticeably curved barrel can still shoot well.
Our job in the aftermarket is to work with or around this range of tolerances and still achieve the desired result. In the case of tube fed lever guns whose handguards attach to the barrel, this can be a challenge, because we want everything to align with the receiver, but the barrel is not running true.
We made a deliberate decision not to use a continuous top rail in order to mitigate the effect of manufacturing tolerances on accuracy. Our past experience as custom lever gun builders taught us that accuracy generally falls off when one ties the receiver to the barrel with a continuous rail. For the same reason, we strongly advise against “bridging” the receiver rail to a Gator Rail with a single optic.