The Road to Mammoth: Getting Good DOPE Part 2

Welcome back! Part one taught us the importance of accurately measuring data from your rifle. Subsequently, Chris will give us the necessary next steps to ensure your freedom seeds land exactly where you intend to plant them. DOPE is on the brain today friends.

Confirm the firing solution accuracy at supersonic and into transonic

By now, you should have all the necessary measurement inputs to populate a complete gun profile. The attention shifts to trajectory prediction accuracy confirmation. Confirmation will  occur in two stages: the first occurring close to the extent of supersonic flight. The second occurring into the transonic flight regime. I separate the confirmation into two stages because the trajectory prediction error in supersonic usually relates to a gun profile input error, inaccuracy, or short-range zero issue. Assuming the supersonic prediction was exact, error into transonic usually relates to how well the bullet transitions through the sound barrier.


In less common instances, the gun might have an initial launch dynamic. This causes some amount of velocity decay, which is a problem that can be determined quickly by using the LabRadar measured downrange velocity data. It may also be necessary to conduct a Drop Scale Factor (DSF) calibration process if a discrepancy exists between predicted and actual transonic firing solutions. Firstly, it’s important to verify supersonic trajectory prediction accuracy and then proceed to transonic to progressively eliminate the likely error sources.

Understand your device features, capabilities, and constraints

Being a master of your tools and equipment extends beyond the weapon system and shooting techniques. For instance, it must include your ballistic solver too. An accurate ballistic solver is the tool that calculates your firing solution. The gun merely allows you to use the information to hit your target. When considered, both weapon and solver are equally important to facilitate success. Also, aim to be just as competent with your AB device as with your rifle. Mastering your device is now quite easy with the amount of information, blogs, podcasts, and formal training that is available. Understanding the device features, capabilities, and most importantly what it cannot do, helps  you understand how the device is employed to attack a stage most efficiently.

Garbage In, Garbage Out (GIGO)

The relationship between GIGO and ballistic solver is a subject that has received a lot of attention.  The accuracy of the gun profile, target, and environment inputs directly effects the accuracy of the firing solution output. The AB Engine breaks the trajectory into many portions called time-steps. Additionally, it solves for the equations of motion and calculates the bullet position at every point downrange. Ballistic solvers are like calculators, so if 2+2 does not equal 4, you’ve sourced bad information. Troubleshoot with the question “What is the source of the error?” and you are already closer to figuring out why the real-time firing solution does not match the trajectory prediction.

Hard copy recording of gun profile and DOPE will provide information helping to diagnose any trajectory prediction inconsistencies. When a calculator gives an incorrect answer, we go back and verify the numbers. When a ballistic solver gives an incorrect solution, we should go back and verify the inputs. You can find a full rundown of Applied Ballistics’ DOPE book in a future article.

A special thanks again to Chris for imparting the “simple” secrets to ringing steel at mammoth or dropping bad guys in their tracks.

Know what we're sayin fam?

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