Tag Archives: Optic

Zero your damn MRDS.

Before zeroing the pictured mini red dot sight, it was impacting 4 feet high, and a foot right at 50 yards.

Some time back I really got into the piggy back mini red dot sight (MRDS) on top the ACOG.  I’ve also run them on top and offset from higher magnification scopes.

So having started running these offset and piggyback MRDS, I got really curious about how other people were using them.  So I asked people, in person and on gun forums.

“Oh, it’s for close range, so it’s not zeroed.”

Now to be fair, there was one person who said he zeroed his at 10 feet.  All the rest had their mini red dots unzeroed.

The point of a firearm is to be able to place rounds on a desired target.  Be that target a piece of paper, prey, or a hostile combatant, we index our firearm on the target in order to achieve that effect on target.  We use our sights to verify that the firearm is aligned and indexed with the target.

It is pointless to have an unzeroed optic.

“But Howard, I’m only going to use the red dot at super close range.”

At close range is there it is most important that your shots are effective.  If you have a less than ideal hit on a bad guy 500 yards out and they take a few minutes to bleed to death, that would just be a shame.  But if up close you fail to instantly neutralize a target, the result could be deadly for you, or those you care about.

The big downsize to having these secondary miniature sights is odd height over bore or offset issues.  These issues can lead to these offset sights being massively off, like the one pictured above.  Offset sights are usually sitting on a stack of mounts attached to a handguard that may or may not be parallel with the bore.  It can be very easy to be multiple feet off target at close ranges with an unzeroed offset sight.  Your average sight on an AR15 is 2.6 inches over the bore.  A piggy back red dot can easily be 4+ inches over the bore.  This height over bore makes picking a good zero difficult.

There is going to be a part 2 to this article, where I will go over some of your options when zeroing an offset or piggyback MRDS.