User guide

Figure 6
5.The next step is to assemble the Diffusers. Each Diffuser consists of 
one middle piece and two end pieces. The notches on the diffuser are
numbered with either a number “1”or “2”to help aid in assembly.
Take the middle piece and one of the end pieces, line up the matching
numbers and simply slip into position (See Figure 7).
Figure 7
6.  Insert the Diffuser’s tab into the Support Arm’s slot so the ribs on the 
Diffuser are facing down toward the Skyscreen as shown in Figure
8.While holding the Diffuser horizontal,install the other Support Arm 
onto the opposite side of this Diffuser and then connect this Support
Arm to the Skyscreen the same way you did in Step #4.
Figure 8
7. Repeat steps 4 – 6 for the other Skyscreen location.
SET-UP
ALWAYS WEAR EYE AND HEARING PROTECTION.
1.  Place the assembledchronograph unit on a stablesurface or tripod 
(not included).Ensure the Chronograph is level and oriented in the 
same direction as the bullet/projectile’s path, otherwise it could give 
you erroneous velocity readings.
2.The Front Skyscreen, for typical rie calibers (.308 or smaller), should 
be at least 10 feet away from the muzzle of the weapon (See Figure 
9).Larger calibers,magnums,etc.,produce more muzzle blast that 
can falsely trigger the Skyscreen and produce erroneous velocity
readings. Increase the distance to 16' - 18' to eliminate this issue.
Figure 9
3.  Bring the Display Unit back to your ring position.Turn the Display 
Unit  on  by  pressing  the  On/Off  button.You  will  see  the  following 
display for a moment while the unit initializes (See Figure 10).
RCBS AmmoMaster
®
Chronograph Instructions 3
1 0 '
4 "