Piggyback VS Offset Optic Mount Setup

ACOG 3.5X on FN SCAR 17



  • Lack cheek weld consistency

Angled Offset Red Dot Mount



  • Night Vision Gear
  • Prone Shooting
  • Better Recoil Management When Canted
  • Shooting Around Cover
  • Low-Light Shooting
  • Wearing Gas Mask
  • Works with center axis relock technique


  • Might not align with bore on some rifles
  • Zeroing at an angle creates POI offset

3 Common Scope and Red Dot Setup Options

Option 1 - Long-Range Setup, Also Short-Range Ready

me shooting guns

For all you long-range DMR fans out there, you like having a heavy-duty, large profile long-range scope on your rifle for distance shooting.

In order to make your setup also close range capable without swapping optics, it's recommended to just add an angled offset red dot sight mount. Tilting the rifle to the side would have the red dot sight picture right in front of you. Some even use offset iron sights to co-witness with the RDS.

This type of setup is the easiest and fastest way to transition from magnified long-range scope to a 1X fixed optic.

Don't have a micro red dot yet? please check out this MRDS buyer's guide.

Note: If you like to mount an offset red dot optic on the scope ring adapter like the LaRue LT 137 J-Point or Spuhr, be sure to check the alignment to the bore.

Personally, I don't like offset scope ring adapter because they don't usually align with the bore, which causes zeroing and holdover headaches. It also increases the vertical profile of the optic setup.

If you're not sure about how to properly zero a offset sight please read here.

Option 2 - Hybrid Red Dot Magnifier Setup

In recent years, red dot sight magnifier combo setup has been super popular. The shooter can flip the magnifier to the side when transitioning back to 1X for close-range targets.

The Aimpoint twist mount allows the shooter to quickly mount or demount the magnifier as needed, which is one of our favorites.

Recently, there are products on the market that allow the shooter to tuck the magnifier down for minimized side profile, like the new Scalarworks and Unity Tactical setup.

Option 3 - 2 In 1 Optic Piggyback Setup

scar17 with Trijicon ACOG with RMR piggyback setup

Sights like the ACOG, ELCAN, Leupold HAMR are made with Piggyback red dot optic adapter. The optic sits right on top of the primary magnified optic.

The shooter just needs to shift his head up or down for transition.

What I like the best about this setup is that this is a 2 in 1 package, and the two aiming reticles are all inline with the bore.

That extra height gives the shooter who wears a helmet and other kits a bit more room to work with.

Note: What I don't like is when the shooter aim through the red dot sight, then lifts up his head and no longer cheek welding the rifle for fast steady shots.

Piggyback vs. Offset Holdover

Red dot sight piggyback offset

Image Referenced MarineCorpsTimes

  • Piggyback red dot sight sits just above your primary sight, and the line of sight sits a bit higher than the bore. The point of aim and the point of impact are more aligned for long-distance shots.

However, at close range distance such as 10 to 25 yards, the shooter needs to learn a new holdover technique and zero

Piggyback setup is not recommended for high height over bore rifle like the Tavor X95 for CQB reasons.

  • Angled offset mount is my favorite because it sits low. All you have to do is tilt the rifle and engage the target as you would with your primary optic. 45 Degree Offset aligns with bore

There is no significant offset you need to compensate for. However, when aiming canted with the primary optic, there will be point of impact shifts.

eotech 45 degree leaning left

Red Dot Sight On Scope Ring Adapter (Angled)

This is my LEAST favorite configuration because the optic sits way too high and they don't usually align with the bore.

If I have to pick a scope ring adapter I would pick on that sits straight on top of the scope rather than at an angle.

I want my red dot sight to be aligned with the bore without learning a new holdover.


Which Scope Mounts Accepts Offset Scope Ring Adapter

LaRue LT137 and Sphur mounts have adapters you can purchase to mount an offset optic. Some are made for piggyback and some are angled.

Other Recommended Dual Optics Setup

Leupold has made a very unique hybrid optic system that combines the LCO and D-EVO together for close-range and long-range.

The shooter can transition from the 1X to 6X back and forth by shifting just their eyes mere 6 degrees.

  • Without adjusting cheek weld
  • Without magnification adjustment
  • Without moving the shooter's head

Good News: The D-EVO is a standalone magnified optic with its own dedicated aiming reticle, and it can be pair with any other red dot sights as long as you're using lower 1/3rd co-witness mount.

Eotech paired with Leupold D EVO

Image Referenced GunsandAmmo

Dual Optic Setup Tips

  • Keep all optics align with the bore to avoid  horizontal holdover
  • Keep offsetting red dot sight as low as possible to avoid significant vertical holdover
  • Place offset angled mount favorable to your dominate side
  • Do NOT zero offset red dot sight at an angle
  • Do Not use scope tube offset mount

Ying Xu

I'm a former US Air Force ICBM operator, and now I'm a veteran creating fun firearm accessories content. I also work as the search engine expert for BadAssOptic.com