To get your rifle to shoot good groups with VLDs, we have provided you with a simple step by step solution below that guides you through the process of tuning these bullets.

All bullets that have a Secant Ogive, like the VLDs, generally have what we refer to as a “sweet spot” for each given rifle. This will vary from rifle to rifle, but is generally a band .030” to 0.040” wide and is located anywhere between jamming the bullets into the lands and 0.150” jump off the lands.

Before we begin, you will need the following:

  1. To know what Cartridge Base to Ogive means.
  2. To know what Jamming a bullet and Jumping a bullet means.
  3. A good CBTO measurement tool, like a set of calipers and a Sinclair Bullet Comparator.
  4. A good reloading press.
  5. Reloading components for 50 rounds of ammo.
  6. The minimum powder charge from the load data for the given bullet, found either in our Reloading Manual or by contacting our Tech Team. You will use this powder charge for all seating depth testing.

First, find what your Cartridge Base to Ogive length will be when a bullet is jammed into your rifle.

  1. Load a bullet in an empty case far enough out that when you close the bolt of your rifle the bullet will “jam” into the rifling.
  2. Chamber this round into your rifle.
  3. Eject the round.
  4. Measure the round using a CBTO measurement tool, this will be X in the following steps.

Load 24 rounds at the following Cartridge Base to Ogive lengths.

  1. 6 rounds at X – 0.010”
  2. 6 rounds at X – 0.050”
  3. 6 rounds at X – 0.090”
  4. 6 rounds at X – 0.130”

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. Find which one shoots best, that CBTO will be used in the following steps as Y.

Load 24 rounds at the following Cartridge Base to Ogive lengths.

  1. 6 rounds at Y + 0.02”
  2. 6 rounds at Y + 0.01”
  3. 6 rounds at Y – 0.01”
  4. 6 rounds at Y – 0.02”

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. Find which one shoots best, that CBTO is your new load!

(Optional) If you want to further refine your load, you can continue below using the above CBTO as Z. You may or may not get additional benefits from this.

Load 24 rounds at the following Cartridge Base to Ogive lengths.

  1. 6 rounds at Z + 0.005”
  2. 6 rounds at Z + 0.002”
  3. 6 rounds at Z – 0.002”
  4. 6 rounds at Z – 0.005”

Shoot 2 (separate) 3 shot groups in fair conditions to see how they group. Find which one shoots best. From there, you can continue adjusting in 0.002” or 0.005” increments if you want to further develop your load. As before, you may or may not get additional benefits from this extra step.

Now that you are done with seating depth testing, it is time to start gradually increasing your powder charge until you find that sweet spot, further increasing your accuracy!