Speed Drop Shooting is a technique developed in order to have your DOPE match your range divided by 100 in an effort to “Speed up” your shooting onto targets. There is debate out there whether it is faster or not, or even worth your time; however, this article is designed to tell you how to achieve the desired data. You make the choice if you want to use it or not.
In Part 1 we discussed how to achieve this using an Applied Ballistics Kestrel 5700; however, not everyone owns one of these or has access to one. In this part we will discuss how to achieve the same result using our known verified DOPE.
Please Note: Speed Drop Shooting has its limitations and will NOT work for all ranges. There is a bracket for each cartridge and rifle where it will work depending on your target size.
Method 2: How do I Calculate Speed Drop?
Using Our Known DOPE
Step 1: List out your known DOPE out to the range you intend on shooting in increments of say 20m from your zero. If you aren’t zeroing at 100m/y for a centerfire you are doing it wrong! We can discuss that another time though.
For this example we will use my data for hand loaded 108gr Hornady ELDM from my Accuracy International AT-X going at 3130fps.
Step 2: Next we need to list out our ranges divided by 100. Eg 260/100=2.6 or 700/100=7.0 etc.
Then we that take that range divided by 100 number and subtract the DOPE number from it. 2.6 – 0.5 = 2.1 or 7.0 – 4.0 = 3.0 etc.
We will demonstrate this in the table below.
I hope you are still following.
Step 3: Next we need to look for a pattern. Ideally you want to look for a broad range of numbers with a +/- 0.2 range in the (Range/100)-DOPE column (Green column)
There may be a small amount of outliers outside of this range. But then again there may not.
Looking at the table above there seems to be a large range of numbers between 2.6 and 3.0
That would give me an average of 2.8 +/- 0.2
Guess what? 2.8 is our Speed Drop Number
Step 4: Now we have our 2.6 to 3.0 speed drop number range. We need to find our actual range in meters these numbers lie between.
Looking at the table above the useable range would be between 400m and 920m.
Step 5: Looking at our data now we can figure out our error in mils for those distances from our actual DOPE. Then using the *mil relation formula we can figure out the error in CM. This will give us an indication of what size target we can effectively engage between 400m and 960m using our speed drop number.
*NOTE: The Mil relation formula is 1 mil @ 1000m = 1m if you didn’t know.
Step 5: Now to use this in a speed shooting type of way dial the 2.8 mils down from your zero then hold your distance divided by 100. Eg: 420/100 = 4.2mils or 800/100 = 8mils.
There we are all done. Now you know how to calculate your speed Drop manually and actually use it.