The primary reason that some people are confused about mags is that they are used to AR-15 style rifles, which DO all use the same mags. These rifles all share a fairly common anscestory and as such, share parts compatibility, mag compatibility, accessory compatibility with each other (for the most part).
When the larger ".308" platforms evolved, each manufacturer, lacking a common base platform, pursued their own designs. Which magazine to use was one of the design decisions that had to be made. Different companies went different ways and ended up with designs that are not made to mirror one another, have parts compatibility between brands, etc....Some ended up using existing .308 mags from other platforms (such as the FAL or G3)mags, some using modifications of existing mags (such as the M14), and some even use(d) proprietary new mags.
Directly to BB's comments, the BAR-10 had its bolt breakage on the bolt's tail, not the lugs. Neither the BAR-10 nor the LAR-8 have ever been lacking lugs on the bolt (bottom or otherwise) as their common basic design allows for a full AR-style bolt face with all lugs in place. The only agreement on the incompatibility of an AR-style bolt and FAL magazines was between a market competitor (who rightly stated that his rifle's design was incompatible with the FAL mag) and himself. With a rifle designed for the use of the FAL mag in mind, it is not, and hasn't been, an issue.
Thanks for allowing me to clarify these points within this thread.
Steve/RRA