Q&A for Leupold RX-2800 TBR/W Laser Rangefinder — 20 Questions & 22 Answers

If you are lucky your load is listed in the owner's manual TBR/W PERFORMANCE GROUPS: LOAD TABLE (page 21 of the owner's manual) but for most of us our load won't be listed. To set up the ballistic calculator to match our rifle and load we must match our rifle's ballistics with the RX2800 TBR/W Load Group Selection Table (page 25 of the owner's manual).

Here's how to determine your "Load Group Number" to make the RX2800's ballistic solution as accurate as possible. You can also figure out a correction when using a 100 yard zero versus the 200 or 300 yard zero that's listed in the RX2800 Load Group Selection Table.

The RX2800 uses Load Group Numbers to categorize rifle ballistics. To find our Load Group Number we'll compare our load's ballistics to the RX2800 Load Group Selection Table (shown above).

Use your favorite ballistic calculator to work up three range tables:

1. Use a 200 or 300 yard zero, zero wind and 600 yards as max range. Write down the 600 yard trajectory in inches.

2. Add a 10mph crosswind from 3 o'clock or 90 degrees and write down the 600 yard wind drift in inches. We do a separate chart to keep vertical wind jump out of our elevation number.

3. If you don't zero your rifle at 200 or 300 yards then do another range table using your actual zero range (I use 100 yards) and no crosswind. Write down the 600 yard trajectory in inches. Since the RX2800 Load Group Selection Table uses 200 or 300 yard zeros we'll use this number to calculate an elevation correction to make the RX2800's ballistic solution more accurate.

These numbers must be in inches to use the RX2800 Load Group Selection Table. I use the free online Hornady 4DOF calculator. Be sure and select the units as inches, not MOA or Mils.

With value #1 and #2 go into the RX2800 TBR/W Load Group Selection Table (shown above) and find where your numbers fit in. You have to match the zero range (200 or 300 yards), value #1 and value #2 in the chart. When you match all three you get the "Load Group Number" you will enter into the RX2800's setup menu. Turn the RX2800 on then hold the Mode button for more than 2 seconds to enter the setup menu. Press the Mode button to move between fields and press the Power button to select values to set your Load Group Number.

If you don't use a 200 or 300 yard zero that the Load Group Selection Table uses we can calculate a correction to compensate. For example, I zero my rifle at 100 yards so I subtract value #3 from value #1 to get my correction. For my Tikka T3x TAC A1 in 6.5 Creedmoor with Hornady 147 ELDM factory ammo gives me a 2665fps muzzle velocity and I zero my rifle at 100 yards. This load gives me 72.5" of bullet path height and 21" of wind drift at 600 yards. That puts me into Group 10 with a zero elevation correction of 0.4mil. I add 0.4 to the RX2800's elevation mil display to compensate for the 100 yard zero. The elevation correction is the same at all ranges. The RX2800's wind solution is for a 10mph direct crosswind and does not need to be corrected.