Date added: 05/05/2011 The ACI
NSN: 1005 01 560 0130
NSN: 1005 01 584 7024
NSN: 1005 01 584 5402
NSN: 1005 01 584 5395
Manufacturers Part No.: ACIMIL-A2
GS - 07F - 0259N
CAGE: 1T5U0 or 3LQE0
DOD EMall Cont. #: SPM7W107DE028
U.S. Pat. 6,568,092
PGM Weapon Systems
Phone:(800)651-1050 Dir.(818)359-0512 FAX:(970)586-9281

ACI Small

The "Angle Cosine Indicator," ®is a simple tool for hunters in mountainous terrain, and utilized to obtain their corrected for gravity distance to target.

The ACI® is a vault solid, water resistant precision instrument; quiet and made from aircraft grade aluminum, which is anodized in a flat black color.

The Co-Sine numbers are Laser Engraved onto the body in five (5) degree increments.

The lens is shatter proof, shock proof and resistant to chemicals such as acetone and cleaning solvents.

Completely mechanical, there are no batteries or electronics to fail.

Battle Proven and in use by:

US Marine Corps


US Army, Special Forces

U.S. Air Force

US Navy

US Border Patrol

British Special Forces

Canadian Special Forces

Australian S.A.S.

LE , Hunters and many others.

ACI Cosine
Angle Degree Indicator
Angle Cosine Indicator™
Angle Degree Indicator™

Images of User's Rifles

PGM Weapons Systems

The PGM .338 equipped with the Schmidt Bender 5 - 25 X 56 and an ACI®

The "A.C.I."™ works on any shoulder mounted weapon system . When the weapon is held at an angle, the "A.C.I."™ indicates the co-sine number of that angle by means of a highly visible index mark. The co-sine number is then multiplied to the "Established Range", (sloped distance to target), or inputted into the data entry point of the users Ballistic Targeting Software, which gives you the corrected for gravity distance to target.

There are several ways to mount the device. One way is to utilize a short, Weaver Base scope ring, which is mounted onto the scope tube, at 90 degrees.

Another way is to utilize a Badger Ordinance mount designed to attach to a picantinny rail. The mount works on all day and most night scopes. Close up of the Badger Ordinance mount. Schematic of Badger Mount

Articles & Testimonies

Magazine Article Sniper's Paradise Article
Gun's Mag. Article Sheep Hunt Hawaii
82nd Airborne Division British Sniper AZ ZUBAYR
Inclined Fire by William T. McDonald Angle Shooting by Ward W. Brien

How does it work? One of two ways, but simple..

Method #1; The most accurate method is to input the cosine number into your ballistic software; i.e. Exbal Ballistic Targeting Software or Field Firing Solutions, that runs on either your home PC, Pocket PC or Palm Pilot. This is because the software takes into account the trigonomics of the fact that the bullet will still travel the full distance to target, and maintain a similar time of flight.

b. Due to discrepancies at shorter distance, we are advising all users of the ACI to only utilize method #1 and #2.

Method #2, is to multiply the cosine number to your sloped distance to target. This will deliver the flat line distance to target, or what we call the bottom leg of the triangle.

If you experiment with your ballistic software, you will find that there can be as much as eight (8) MOA difference between method #1 and method #2. Method #1 is the most accurate & preferred method.

Now, adjust the sight elevation knob (come-ups) on your scope, for the "corrected range".

ACI For Hunting

Bryan Martin of Canadian Mountain Outfitters

Ian's Occupied Rock & Erwin's

R & D Precision Gunsmithing