This is a technique I used to cut some KAC rail covers to fit the RIS II hand guard.  

This guide is mainly meant for people who want to use the Taupe panels, since they seem to only be available in 11 and 6 rib varieties.


Before you get started you will need the following:

- Sharpie marker
- Hack Saw
- Grind wheel
- Emery cloth or sand paper


I want to preface this with one warning: GO SLOW and TAKE YOUR TIME

It is very easy to cut or grind off too much material, and then you have a useless panel.  Measure twice, cut once.


Having said that, I'll jump right in.

Here we have a pair of RIS II hand guards.  One is a Mk18 and one is a M4A1.  If you slide an 11 rib KAC panel onto either of them, you notice that you are left with an odd amount of space of the front end.






To get a rail panel that fits correctly, you'll have to take an existing 6 or 11 rib panel and cut it down.

For the Mk18 hand guard, I've selected a 6 inch panel.





I notice that the cut will not fall perfectly on the edge of a rib, so I'm going to cut it on the rib and shape it accordingly.

Here, I mark it with a sharpie, leaving a little bit of extra space on it for fine tuning on the grind wheel.





After carefully measuring both, I now have an idea of where to start cutting.





On to the hack saw...






I'll say again, GO SLOW.







After the hack saw, the panels are close to where they need to be, but still require some fine tuning.







The grind wheel gives you very precise control over how much material is being removed.  This is probably the most critical point where you need to take your time, because you can very easily ruin your rail cover if you rush and take too much material off.







As I grind, I take the cut rail cover and compare it to an unaltered one to make sure the profile looks correct.  I will add the chamfer once the length is right.







With the length correct, I slowly grind in the chamfer.  This takes a lot of attention to detail, but once it's done, you can barely tell the difference between the new cover and the factory one.







For the Mk18 cover, I had to take the last rib completely off.  I continually slide the cover on the rail to check the fit.







Finally, I hit the ends with a little emery cloth.  Again, go nice and slow and your results will be great.







When it's done, the look like they came from the factory that way.



From left to right:  11 rib panel, custom 9 rib panel, custom Mk18 panel.








I hope you found this helpful.

Good man, thanks for posting!

Bump for people who are interested.

I've done this with a miter saw. It's faster and cleaner than hack saw. Then finish off with various grits of sandpaper.