Bullet drop: D.O.P.E.

Accounting for bullet drop with Data On Previous Engagements (D.O.P.E.) provides options for field expedient and remarkably accurate adjustments to be made when the in game range card is rendered obsolete, or when shots must be taken at extended distances. Gathering the information required is a time consuming investment, however, those inclined towards this hands-on method are at an advantage as the details gathered will precisely account for the effects of temperature and air density, removing the need to independently account for these variables altogether.

Data collection

To assemble D.O.P.E. for bullet drop, targets must be placed at known distances. Shots should be taken at these preplaced targets, and the vertical adjustment that is needed to counteract bullet drop due to gravity should be recorded for the respective distances. This vertical adjustment is the information that will be used in operation to impact targets at distance.Note: even with no wind present, the bullet will drift increasingly to the left or right with distance - this drift is the product of spin drift and horizontal Coriolis working together. This information may easily be recorded alongside gathering D.O.P.E. for bullet drop.

Target Range	*Vertical Deflection*	Horizontal Deflection
400m	-2.6	0.1 R
450m	-3.1	0.1 R
500m	-3.7	0.1 R
550m	-4.4	0.1 R
600m	-4.9	0.1 R
650m	-5.5	0.1 R
700m	-6.5	0.2 R
750m	-7.3	0.2 R
800m	-8.0	0.2 R
850m	-8.9	0.3 R
900m	-9.8	0.3 R
950m	-10.8	0.4 R
1000m	-11.7	0.5 R

D.O.P.E. assembled by a sniper team using an M24 SWS

When collecting D.O.P.E. of any kind, it is critical that collection atmospherics match the operation atmospherics. In the case of measuring accurate vertical deflection, we will need a range environment with:

• The same bullets, rifle and scope that will be used in operation
• Wind turned off
• Weather matching operation conditions
• Altitude matching operation conditions
• Using a level firing range
• Shots only being taken facing directly north or south (to avoid Eötvös deflection)

These conditions can be easily achieved by collecting data on the map in use by the operation, by matching the date and time in the editor to the values set on the mission file, and ensuring wind is turned off. To obtain the date and time in use by the mission file, communication with the senior game master is required.

D.O.P.E. example

Sgt McShooty is deployed as a Spotter (Manual) on a Honeybadger. He ranges a priority target at 900m and has prepared D.O.P.E. for his engagements:

Target Range	Vertical Deflection	Horizontal Deflection
900m	-9.8	0.3 R

He recorded that he needed to adjust 9.8 mils up to impact at 900m, so he gives the sniper a vertical adjustment of 9.8 up, accounting for the effects of gravity, temperature and altitude simultaneously.

D.O.P.E. limitations

As with all instances of D.O.P.E., the data assembled is only accurate for the atmospherics in which it was recorded. When these factors change, such as with changes in temperature, altitude or humidity; our recorded information becomes increasingly inaccurate. With small atmospheric changes, such as with normal temperature fluctuations that are seen over the course of a 2 hour operation - adjustments to recorded data can be estimated with success. When larger changes occur, such as with an entirely different set of atmospherics on a separate operation entirely, adjustments to recorded data can no longer be reasonably inferred, and new D.O.P.E. must be assembled.