SNIPING OPERATIONS EXECUTIVE

To: Dr. John Taylor

Prepared by: Dean Michaelis

Date: 4/23/2001

Re: Ballistics Analysis of the 408 CheyTac Cartridge / 419 gr. Heavy Bullet Configuration

This study confirms the preliminary ballistics report written to determine the potential capabilities of the .408 CheyTac cartridge.

This analysis contains information on the Danger Space dimensions of the .408 CheyTac cartridge. Many external ballistics analysis contain information such as remaining velocity, remaining energy (ft. lbs.), bullet drop, etc. Much of this information is useless to the tactical sniper as it is generally considered that if you can hit the target under unknown distance conditions, you will put that target down. Energy is irrelevant with a 419 gr. bullet at 2000 meters if you can simply strike that target. What counts for the tactical sniper when considering a weapon of suggested higher performance than his current weapon?

How accurate do I have to be in my range determinations.

How much better does this new system resist deflection caused by wind.

How resistant is this new bullet in flight to changes in air temperature, barometric pressure, etc.

 

The Danger Space dimension tells the sniper how much error his can make in his range determination and still strike the target within allowable parameters, usually considered to be 2 minutes of angle. With that said, it is acceptable to state that the size of a target at ANY range is only two minutes of angle, or the

size in inches representing that 2 Minute of Angle figure. When considering a new rifle/ammunition it is quite reasonable to consider the most important pieces of data as Danger Space and Resistance to Windage Deflection. All other pieces of information would serve to support the above data.

Data for comparison is used for comparison against selected high performance cartridges and bullets in use with current military cartridges. The cartridges and data used are as follows:

  M118 / M118 (LR) Special Ball Current issue for the M-24 SWS, USMC M40A1 and Naval Special Operations SWS.

  A-191, .300 Winchester Magnum: The current cartridge for the very limited service, M-91 .300 Winchester Magnum. This rifle is very limited in issue. It is available in Naval Special Warfare units and available to US Army SOF units through the Joint Operational Stocks facility.

  .338 Lapua (for comparison only): Not currently in use within the US military or SOF units. Configured with the .300 gr. Sierra Matchking at a velocity of 2850 fps.

  .50 BMG, Mark 211, MOD-0 (Raufoss): Current military cartridge of choice for the .50 caliber SWS. In use by all branches of service.

  .50 BMG, 750 Gr. Horn day AMAX (for comparison only): This configuration is being considered for limited special issue to US and Allied Forces.

  .408 CheyTac, 419 Gr. Lost River Ballistics bullet. The data used to determine the ballistic characteristics of the .408 are finalized. The ballistic performance of the 419 gr. bullet predicted in the previous report is confirmed in this report. The base ballistic co-efficient of the 419 gr. bullet is .903 when launched at a velocity of 2890 fps.

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EXECUTIVE SUMMARY: This summary gives the key gains of the .408 CheyTac cartridge over the three primary military sniping cartridges used by US Armed Forces at this time. This includes both the conventional and Special Operations Forces available weapons and cartridges. The cartridges listed that are NOT part of the US inventory will not be covered in this summary. Performance data is listed in order or precedence for the ranges listed.

DANGER SPACE DATA: Data is presented for a desired kill zone on the target of 2 Minutes of Angle in size at the given range. See tables for actual Danger Space dimensions additional data.

At 1000 meters, the 408 is 179% more efficient than the M-24SWS / M118, 36% more efficient than the .300 Winchester Magnum and 51% more efficient than the .50 Caliber SWS / Raufoss.

At 1500 meters, the 408 is 61% more efficient than the .300 Winchester Magnum / A-191 and 85% more efficient than the .50 Caliber SWS / Raufoss.

At 2000 meters, the 408 is 85% more efficient than the .50 Caliber SWS / Raufoss.

WINDAGE DEFLECTION (given in inches for a 10 mph crosswind) DATA:

At 1000 meters, the 408 is 178% more efficient than the M-24SWS / M118, 66% more efficient than the .300 Winchester Magnum and 66% more efficient than the .50 Caliber SWS / Raufoss.

At 1500 meters, the 408 is 76% more efficient than the .300 Winchester Magnum / A-191 and 74% more efficient than the .50 Caliber SWS / Raufoss.

At 2000 meters, the 408 is 68% more efficient than the .50 Caliber SWS / Raufoss.

ELEVATION REQUIREMENTS (Minutes of Angle) DATA

At 1000 meters, the 408 is 95% more efficient than the M-24SWS / M118, 12% more efficient than the .300 Winchester Magnum and 26% more efficient than the .50 Caliber SWS / Raufoss.

At 1500 meters, the 408 is 29% more efficient than the .300 Winchester Magnum / A-191 and 50% more efficient than the .50 Caliber SWS / Raufoss.

At 2000 meters, the 408 is 57% more efficient than the .50 Caliber SWS / Raufoss.

408 CheyTac Sensitivity to Changes in Air Temperature.

The .408 CheyTac is 92.9% at 1000 Meters to changes in the air temperature, 125.6% at 1500 Meters, and 130.1% at 2000 Meters more efficient, than the current military .50 caliber military round of choice, the Mark 211, MOD-0 Raufoss cartridge.

408 CheyTac Sensitivity to Changes in Barometric Pressure.

  The .408 CheyTac is 106.3% at 1000 Meters to changes in the barometric pressure, 128% at 1500 Meters, and 109.2% at 2000 Meters more efficient, than the current military .50 caliber military round of choice, the Mark 211, MOD-0 Raufoss cartridge.

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General: In military sniping, the main critical factor that snipers must determine is the range to the target. Failure to do this with required accuracy makes all other data, calculations and corrections moot. Snipers that are going to engage targets in the 1500 meter + spectrum must determine the range to the target with extreme levels of precision. There are no instruments in use at this time that allow the type of precision needed to engage 2 Minute of Angle targets to ranges of 1500+ meters.

The major factors in determining the range depends on several factors. These include:

The ability of the sniper team to see the target.

The quality of the optics used to determine the range to the target.

The method of rangefinding itself.

The willingness of the target to stand still long enough for most taught rangefinding methods to be used.

The skill of the sniper team in rangefinding.

There are three points of data that are used to compare the above mentioned cartridges against each other to show the gain of one cartridge over the other at the ranges indicated. These data are:

 

Danger Space Dimensions (Table 1a, b, c).

 

In military sniping we use the figure known as "Danger Space" (DS) as a ruler to use when determining the range to the target. In determining the danger space for a given cartridge, scenario and range we need three pieces of information:

Height of the target. Clearly the overall height of the target is NOT what the sniper is trying to hit. For the purposes of this document, several allowable strike zone measurements are used. These are presented in Minutes of Angle and inch dimensions in the table data. (1a, b, c) Normally the total height of the target is used in this data. For sniping we have to use the height of the critical killing zone on a target. While the height of a 6 man will yield a workable Danger Space figure, we have to hit a much smaller target that 6. We use the standard of 2 Minutes of Angle. So at 1000 yards the height of the target becomes 20".

 

Fall Angle. We must know the fall angle of the bullet as it passes through a vertical plane at the range at which we are shooting. For the 7.62mm NATO at 1000 yards this angle is 1.4197 degrees. The steeper the angle of fall of the bullet, the shorter the Danger Space dimension will be. This means that any range determination must be that more precise. Shallow fall angles result in more allowable range determination error.

 

Range in Yards or Meters. This is needed a part of the DS formula.

 

Another piece of information needed is the height of the barrel off of the ground. In low angle trajectories (under 10 degrees) and in ranges past 600 meters, this factor is small and is ignored. When considering an intended range of 1200 meters, the ability of handling unknown distance problems is paramount. The data in this study is used to show the effectiveness of three cartridges in overcoming some of the shortfalls in performance and training for military snipers. Range finding is difficult and at times impossible. Rangefinding at night is nearly impossible with current issued systems.

 

Elevation Requirements (Table 2): This data is a comparison of the elevation requirements of the cartridges that are listed. Essentially, whichever cartridge needs the least amount of elevation at any given range is more efficient (for elevation) than other cartridges listed. The data is presented in increasing efficiency from left to right. Each cartridge is listed in ascending order. A percentage of gain is presented to show the level of efficiency of one cartridge over the one previous. The .408 CheyTac is the last listed cartridge along with a percentage comparison against all other cartridges.

Windage Deflection Data (Table 3): This data is a comparison of the windage deflection of the listed cartridges by a 10 mph wind at the ranges indicated. The next most difficult factor (after range determination) of combat sniping is that of wind determination and correction (authors opinion). Each cartridge is listed in ascending order. A percentage of gain is presented to show the level of efficiency of one cartridge over the one previous. The .408 CheyTac is the last listed cartridge along with a percentage comparison against all other cartridges.

Additional Data (Tables 4 and 5): This data is a comparison of the listed cartridges sensitivity to changes in air temperature and air pressure. The air temperature data (table 4) reflects the effects on the bullet in flight over a temperature range of 30 to 110 F. The air pressure data (table 5) reflects the effects on the bullet in flight over a Barometric Pressure range of 26.53 In. Hg. 31.53 In. Hg.

Technical Description of the Terms Danger Space, Danger Range, and Swept Space as it applies to tactical sniping or shooting under unknown distance conditions.

GROUP SHOT AT 2300 YARDS

VERTICAL SPREAD OF .50 MOA

HORIZONTAL SPREAD OF 1.7 MOA

419 GR. LOST RIVER BALLISTIC TECHNOLOGIES BULLET

83.50 MOA ELEVATION

Table 1a: DANGER SPACE DATA /// 1000 METER SHOT

The term "height of target" is synonymous with the desired size of a shot group. Presented in inches and Minutes of Angle.

Table 1b: DANGER SPACE DATA /// 1500 METER SHOT

The term "height of target" is synonymous with the desired size of a shot group. Presented in inches and Minutes of Angle.

Table 1c: DANGER SPACE DATA /// 2000 METER SHOT

The term "height of target" is synonymous with the desired size of a shot group. Presented in inches and Minutes of Angle.