The ejector on the C is more like the one on the HK stuff. It is sprung to keep the nose of the ejector down. The bolt carrier pushes the back of the ejector down forcing the nose up into the groove in the bolt. Height of the trigger housing is pretty critical and adjusting it will allow you to tune your ejector.

With the L model the ejector has a spring under the nose that forces it up at all times. The carrier is still able to push the back end of the ejector down forcing the nose up but it is less critical because the spring will keep the nose of the ejector against the bolt even if the trigger housing is a little low. If the housing is high you can't move the bolt/carrier back as it will bind. So while the ejector itself is similar to the C and the HK it operates a little different.

The nose of the L ejector has a bevel to it that we don't see on any of the HK stuff and I don't recall seeing any other ejectors like it. Most have a sharp point with material falling away from the point of contact in order to insure the ejector hits a point close to the primer on the case head. This insures the case is kicked out sharply. If the ejector point hits too close to the edge of the rim the cases are pushed with less force, more rolled out of the port. My guess is that the Spanish design was done that way to reduce the load on the trigger housing and retaining pin. Having a case slammed into the ejector puts a lot of force on the pivot/retaining pin and can bend the aluminum housing to the point that the pin will fall out or the ejector fail to operate. The spanish trigger housings appear to be made from pretty soft material so this could be a problem. So the ejector is beveled to sort of roll the case out of the bolt and out the port. It works ok if everything else is right but doesn't take a lot to start messing up. Compare to the HK type ejectors and you'll see what I mean.

Lastly, if the bolt gap is too big or too small the bolt velocity can be excessive. This can cause all sorts of problems that frequently show up as cases dropped in the receiver. Sometimes they are dropped off the bolt face due to weak extractor springs or worn extractors. Sometimes they are actually properly ejected but the bolt speed causes the case to bounce off the edges of the ejection port and bounce back into the receiver. Its amazing how fast the cases spin and it only takes a little bit of the case hitting the wrong place to spin it back into the receiver. Look at your cases and see if you can find dings in places they shouldn't be.

Hope something there helps....