Backup Iron Sights probably got their start by doing absolutely nothing when an optic was bolted onto a rifle that came from the factory with irons. But when modern sporting rifles (or whatever silly name the AR15 is being force-rebranded as these days) irons became an deliberate option. BUS or back up sights (whether iron or not) appeared as conventional sights left in place, as well as sighting tools such as notches and even dedicated sight-like things bolted onto scopes, red dots and anything else someone somewhere thinks might fail.
Where the problem really started is with the quality, cost and effectiveness of our current crop of backup sights. The BUS concept was just too great to ignore in the highly unlikely event that a battery would die four years too soon, or amazingly strong optics in cushioned metal tubes might crack. Or that drop out of a helicopter knocks your scope out of alignment but leaves the rest of your gun safe to operate. In other words, people wanted to use the fabulous iron sights as well as their optics extracting the benefits from both.
The odd thing about the Magpul MBUS Pro Offset Iron Sights are that they are not just for backup anymore. In fact the term “backup” has been relegated to just a single letter in the MBUS trademark, and never mentioned again. By offsetting the sights, they work fine even with a heavy optic running on the top rail. In fact, they don’t just back up the optic, they supplement it by being just as effective doing their job as a 3-9x scope. And the offset aspect of these offset sights allows a natural platform for iron sighting with a slight twist of the gun. Forty-five degrees to be exact. So perhaps a MOSS (Magpul Offset Supplemental Sights) trademark is in order?
Read more – Survival Cache
(featured image courtesy of ar15vault.com)