Delta III SD | Delta IV | Delta V | Product Comparison Chart

Delta V©

This program can be purchased only on an SD, a mini-SD, or micro-SD card; it will run ONLY on PDAs that come equipped with an SD port.  It will not function in an adapter used for other ports.  The operating system on the PDA must be, at a minimum, WM 5.0 or above.  The software may be purchased only through our exclusive distributor:

Ashbury International Group, Inc.
84 Business Park Circle
Ruckersville, Virginia
Tel: 434.296.8600
Richard Hall, Marketing Director

This program has all of the features and functionality of the Delta IV except that it comes pre-loaded with bullet profiles and rifle profiles germane to the U.S. military. In addition, the range finder list includes range finders that are used by the military, some of which are not available to non-military buyers including the STORM, RULR, Viper II, and the Vector 21.

Some of the more important features include:

1. As mentioned, the program and all related data files are on an SD card; the program starts upon card insertion and stops upon withdrawal. No data is left on the PDA. This is a much more secure arrangement and insures that data will not be lost if the PDA is damaged. No license keys are required. The program is not installed on the PDA so it can be used on any PDA that has an SD slot (or mini-slot.) (This means that TDS Recon units will not run this software; the TDS Nomad will.)
2. A log key which logs shots taken to include date, time, location, MET variables, shooter, bearing, range, elevation and windage. This log is editable and may be saved on a per mission basis for later use and/or documentation.
3. Additional computation tools to 1) compute/verify muzzle velocity through a point-of-impact method at range when a chronograph is not available; 2) compute bullet ballistic coefficient for use with the program. Although the G1 ballistic coefficient published by most bullet manufacturers is very close and can be used by the program with good confidence, at extreme ranges a more precise number is required and this tool allows the user to obtain a ballistic coefficient that is better than the manufacturers G1 ballistic coefficient, at least for use in this program.
4. Rifle profiles that can have multiple cartridges associated with the designated rifle together with elevation and windage offsets for each cartridge. This cartridge list is available with a single button click from the main page so that switching cartridges does not require loading a new rifle profile. Further, because each cartridge has associated elevation and windage offsets, selecting a new cartridge that otherwise has a different POI than the default cartridge, the offsets allow seamless use of the selected cartridge without having to change or adjust for the different POI.
5. Offset profiles that can be used when one shooter is replaced by another on the first shooter's rifle. The second shooter may need to correct the impact point due to the way he manages the rifle and scope and the offset profile permits him to load the necessary elevation and windage offsets so that he does not need to re-zero the scope or to mentally adjust firing solutions by the offsets.
6. Serial port interfaces for commercial laser range finders that output range, bearing and angle. Each time the range finder is used to range a target, the data is brought into the program at various locations to: 1) automatically compute a firing solution; 2) compute the target's coordinates so as to quickly create target files; 3) or to create direct ranging files.
7. An advanced set of conversion factors and equations useful for long range applications.
8. One click access to rifle profile lists, offset lists and target lists with the ability to quickly edit or create files on these lists.
9. Size-of-Objects database accessible from the reticle ranging form with the ability to quickly import the size of a selected object, using either English or metric units, into the form to complete the ranging of the object.

See the Comparison Chart for additional functions and features.

Why the POI Method for Obtaining Muzzle Velocity is an Important Tool
As the manual points out, chronographs are not self-calibrating; it is not known whether the velocities they output are correct or not. While chronograph data errors, even if erroneous by 10% or even 15%, will not show up when shooting under 500 meters, at longer ranges the errors in muzzle velocity, even small errors, will produce inaccurate trajectory data.

Feedback from military personnel operating in Iraq indicated that a non-chronograph method of obtaining or verifying muzzle velocity was needed in order to test new lots of long range ammunition as well as scavenged ammunition. The POI method was derived wherein the user shoots at a target somewhere between 300 to 600 meters and notes whether the group is impacting above or below the point of aim. The program subtracts the scope error (the difference between the total value of the clicks and the computed elevation - the dialed elevation and the computed elevation will almost never be the same) and then computes what muzzle velocity is required to print the group where it actually is on the target.

It turns out that this method is an excellent way to check the accuracy of the chronograph because it is highly accurate and clearly can be a better data point than that obtained from the chronograph. Even if the chronograph is used initially to obtain a muzzle velocity, the POI method should be used to verify the data. Once a valid muzzle velocity has been obtained, it can be used to calibrate the chronograph by suggesting an error rate or percentage that can be used to correct chronograph output. And this allows the user to compute a better ballistic coefficient for use in the program.

Obtaining a Better Ballistic Coefficient
To compute a ballistic coefficient two velocities are needed: a muzzle velocity and a downrange velocity. The further downrange the better, but realistically since a chronograph will be used to obtain this velocity, the range has to be close enough so our chronograph is not hit by an errant bullet. Max range will therefore probably be between 300 and 500 meters. First the chronograph is used to obtain a muzzle velocity, then the chronograph is placed downrange to obtain a second muzzle velocity. The ballistic coefficient workspace is then used to compute a trial ballistic coefficient. If the muzzle velocities are erroneous, this calculated trial BC will also be erroneous. Example: If the velocities were high by 10%, the calculated BC will be larger by about 5%. A way to correct for the chronograph velocities is obviously needed.

By using the POI method of computing a muzzle velocity, two important data points are obtained: an accurate muzzle velocity and a means to compute the error of the chronograph by simply dividing the chronograph value by the POI method value. This error rate can then be used to correct the downrange chronograph velocity. Of course, this supposes that the chronograph has a consistent error rate. This cannot be determined for certain, but this is probably a decent assumption and better than taking the downrange result at face value.

Using the corrected velocities, a good ballistic coefficient can then be computed for that bullet and it will probably be different from the value given by the manufacturer. Using this newly derived ballistic coeficient and using the POI Method workspace, the muzzle velocity is then re-computed. If the muzzle velocity is altered appreciable, go back to the BC computation workspace, calculate a new error factor, derive a new downrange velocity and re-compute a new BC. This iteration process is repeated until both the computed muzzle velocity and BC don't change materially. At that point very accurate values for both muzzle velocity and ballistic coefficient have been computed and may be used with a high degree of confidence to produce excellent theoretical trajectories.

Deliverables
The Delta V can be delivered in the standard size SD card with not less than 1 Gigabyte of memory or as a mini-SD card with the same amount of memory and housed in an adapter for use in regular sized SD card slots.