RAS Tuning Instructions

Accuracy with RAS - The Tuner Experts
Instructions - RAS Rifle Tuning Systems

The purpose of a RAS Muzzle Brake Tuning System is to reduce the felt recoil and improve the rifle's accuracy . The recoil reduction is built into the muzzle brake design. The improvement in accuracy is accomplished by turning the Tuning Ring as shown in figure 2. As the Tuning Ring is rotated the group size will change as shown in figure 1 below.

The following was shot in an AR15 with 16" barrel and 63 gr. Sierra SP bullets. With the flash suppressor the 2 shot groups averaged 0.96 inches. You can see the improvement with the RAS AR15 Mk III Tuner System.

AR-15 Tuning Instructions Figure 1
Figure 1

An Index label has been provided with the RAS system to aid in this process (shown in figure 3). The Index label has marks 0.050 inch apart. It has been assumed that your rifle has either a 1/2-28 or 5/8-24 threaded tenon on the end of the barrel for a Flash Suppressor. If not a tenon will need to be added before a RAS system can be installed. For the larger barrels and larger RAS systems a 3/4-32 or 7/8-32 tenon will be required.

AR-15 Tuning Instructions Figure 2
Figure 2
  1. Remove the rifle's magazine, open the action and check to assure the weapon is empty. Check the hole size of the end on the muzzle brake to assure it is larger than the size bullet you will be shooting. The RAS-AR15 is bored for a .224 bullet and the RAS-AR10 is bored for a .308 bullet.
  2. Remove the Flash Suppressor and replace with the RAS System. Insert a pin through the holes in the muzzle brake and tap to assure the muzzle brake is tightly secured on the rifle barrel. Turn the Tuning Ring all the way forward until it is snug against its stop.
  3. Attach the Index Label provided (Figure 3) so that it is centered over the top of the barrel.
  4. AR-15 Tuning Instructions Figure 3
    Figure 3
    AR-15 Tuning Instructions Figure 4
    Figure 4
  5. Using a felt tip pen or other marker to put a mark on the top of the Tuning Ring opposite the 0 on the index label. See figure 4.
  6. Load 2 rounds in the magazine.
  7. Carefully shoot a 2 shot group and observe its size. Repeat with a second 2 shot group. Is there a big difference in the size of the groups? If so, then continue to the following step.
  8. Remove the magazine and open the bolt. Turn the Tuner Ring one unit.
  9. Load 2 rounds in the magazine and repeat #6.
  10. Continue this process until best groups are found. Typically the best sweet spot groups will be smaller than the baseline groups by 40%, or more.

Some Comments on Tuning:

AR-15 Sample Target