The LM rails were a popular mounting solution in the previous decades in Europe. It has since then been almost entirely replaced by other, more modern mounting types. This rail is prismatic in its cross shape, with the angles of the rail placed at a 70° angle – therefore it was also known as the 70° prism rail. At the base it was 15 mm wide. The old rifle scopes had the LM rail attached to them at two points. The first point of securing the scope was on its objective. It was done quite similar to that of the Suhl or German Claw mount. The other point of contact was situated on the rifle scopes main tube, about the same place as it is done today. For this reason the LM rail was thin at one end and thick at the other. There was also a difference of height of both rails and in most cases custom mounting solutions had to be made to compensate for this difference.
In the past there weren't so many standards. That is why almost every single LM rail was individualy fitted and custom finished to join the rifle scope with its firearm. The results were higher costs and non interchangeable parts. In order for the rail to stay in its place and not to compromise the shooting accuracy it was fixed to the rifle with a hole bored through the rail and the rifle, which was later fastened with a screw. It acted as a recoil stop as well. In todays world there is almost no producers of scopes with LM rail on the market.