ERA-TAC Angle Cosine Indicator mount with anti-cant bubble level and optional ACI

  • £000

Due to number of options available please contact us for a price.

To order please call us on 01767 834 134 Tues - Sat 10:00 - 18:00 or complete form here

The ACI mount fits the UNIVERSAL interface on your ERA-TAC mount.

The Angle Cosine Indicator (ACI) is an indispensable tool for long distance precision shots when aiming up or downhill. The ACI helps you to easily calculate and correct the gravity‘s effect on your bullet‘s trajectory. The bubble level enables the shooter to understand if the gun is completely level. The ERA-TAC mount with ACI and bubble level can be easily attached to our UNIVERSAL-interface. It is not necessary to alter the position of the scope. The position of the ACI is such that the red needle is visible even when using a scope with the illumination control on the left side and while already aiming.

The position of the elevation turret remains always visible because of the lateral bubble level.

How to use the ACI:

  1. Measure the distance to target by your rangefinder or your scope‘s reticle
  2. Aim at the target and read the number shown on the Angle Cosine Indicator; multiply the actual

distance by the shown cosine number to get the adjusted distance for gravity.


  1. Measured target distance: 800 m
  2. Cosine number shown on ACI while aiming at target: 0.87
  3. Adjusted distance to target: 800 x 0.87 = 696 m

For full range and technical specifications, please consult the catalogue found here

Unless otherwise stated the price is for a single item, in one colour.

Parabellum Consulting Limited accepts no liability for the use (or misuse) of this equipment.

Standard delivery time is 2-3 working days. If a specific item is not in stock then delivery will be approximately 8-12 weeks.

Pictures are for reference; product delivered may differ slightly to that shown.

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