To be honest, that title is rather tricky, and not just because I'm using the word "best" when only comparing two objects, rather than three or more. Know what I'm sayin'? Where my grammar trolls at?

Before I get into the RIS vs. RAS comparison, let me first specify the components of the two acronyms.

RIS = Rail Interface System
RAS = Rail Adapter System

There are actually quite a few variations of those two out there but after doing a bit of mild research on several major firearms manufacturer sites (e.g. Daniel Defense, Knight's Arm Co, etc), as well as a few other gun-related informational sites, I've determined that those are probably two of the more correct meanings. However, since there doesn't seem to be a standard definition that covers multiple manufactured rails, I'm not sure if there's a wrong answer either.

So what the heck is the difference between RIS and RAS then?

Find out after the jump...