Magpul is releasing a new version of its MBUS back-up iron sights. The MBUS Pro differs from the original in a couple of important ways. They are much smaller and they are made from metal instead of polymer, as the originals were.
I’m guessing the changes had something to do with Magpul getting sick of trying to overcome the market bias against the perceived weakness of “plastic” sights. We’ve got a set of MBUS and haven’t had any issues with them at all despite our predilection for rough handling.
Making the new sights from metal automatically reduces the material needed to produces the sights when compared with polymer, which is a less dense material. So, the move from polymer to metal gave Magpul an opportunity to go smaller, and it looks like they took that ball and ran with it.
Magpul has experience making metal parts, so this isn’t a massive departure for the prolific pushers of professional grade polymer parts.
Even if you’re a professional gunfighter, BUIS are more like jewelry for you carbine than anything else. These days optics the wide array of quality combat carbine optics have become so reliable that transitioning to irons in-extremis may happen once — or never — in a modern gunfighter’s career. So keeping the weight and bulk down on such a rarely relied-on part of the rifle makes perfect sense.
And, at $190 a set, there are plenty of guys who would rather spend that money on a piece of life saving kit like this than a pair of gold-plated cufflinks. More information on Magpul’s site: http://store.magpul.com/category/44.