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Finding your Speed Drop Factor
- Thread starter Lowlight
- Start date
This could be a game changer. When used with a fatal funnel or a spotter calling range, dialling elevation and making hits would happen extremely quickly with this method.
If you need more precision, keep a correction card with your +- values for fine tuning on smaller targets. A correction card would also help you extend the usable Range of this method.
You could even go one step further and work out the initial speed drop factor for your average density altitude and have another dope correction card for higher/lower density altitudes.
EG
Turret set to average DA SDF.
Slip turret to +- density correction at the start of your shooting session or to the expected DA at location (monitor and adjust as needed)
Range target,
Dial yardage,
Dial +- correction,
Send it.
Very, very cool stuff.
If you need more precision, keep a correction card with your +- values for fine tuning on smaller targets. A correction card would also help you extend the usable Range of this method.
You could even go one step further and work out the initial speed drop factor for your average density altitude and have another dope correction card for higher/lower density altitudes.
EG
Turret set to average DA SDF.
Slip turret to +- density correction at the start of your shooting session or to the expected DA at location (monitor and adjust as needed)
Range target,
Dial yardage,
Dial +- correction,
Send it.
Very, very cool stuff.
I first ran this out at accuracy 1st a few years back. It is a awesome way to engage targets. They did state that it is not a precision tool it’s mainly an RTE tool just like 12” drill or 2/4 mil drill. However it’s a great way to get an initial shot on target
Depending on your load/distance - it might also work better with range in Meters rather than yards. I used it to make a quick demo to a buddy engaging 2 moa steels at 300, then 400, then 500, no maths - all hits. It's really quick and if you set it up for +/- 0.1 mil instead of the default 0.2 it's pretty accurate and as opposed to a BDC, it will change depending on your load/weather/env - somedays it might be 2.2 instead of 2.0.
Really cool feature, if Strelok would offer it, I'd probably sell my 5700 Elite.
Really cool feature, if Strelok would offer it, I'd probably sell my 5700 Elite.
You have to calculate your speed drop manually unlike the Kestrel but you can use Speed Drop with the Strelok Pro app.
Do you need to be somewhere north of 2600 fps for this to work? Not sure what I am doing wrong but my 73g ELDM's from my 13.7" barrel gives some wacky readings on the table. The gun itself has no issues with accuracy out to 800...very consistent. Would like to be able to use a table like this if possible, my MV is 2440 fps @ 60 degrees:
| Yards | Drop/Mills | Factor |
| 150 | 0 | 1.5 |
| 175 | 0.2 | 1.55 |
| 200 | 0.4 | 1.6 |
| 225 | 0.6 | 1.65 |
| 250 | 0.9 | 1.6 |
| 275 | 1.1 | 1.65 |
| 300 | 1.4 | 1.6 |
| 325 | 1.7 | 1.55 |
| 350 | 2 | 1.5 |
| 375 | 2.3 | 1.45 |
| 400 | 2.6 | 1.4 |
| 425 | 3 | 1.25 |
| 450 | 3.3 | 1.2 |
| 475 | 3.7 | 1.05 |
| 500 | 4.1 | 0.9 |
| 525 | 4.5 | 0.75 |
| 550 | 4.9 | 0.6 |
| 575 | 5.3 | 0.45 |
| 600 | 5.8 | 0.2 |
| 625 | 6.3 | -0.05 |
| 650 | 6.8 | -0.3 |
| 675 | 7.3 | -0.55 |
| 700 | 7.8 | -0.8 |
| 725 | 8.4 | -1.15 |
| 750 | 9 | -1.5 |
It only works out to a certain distance. Looks like your speed drop number is a 1.5/ 1.6, that’s if you except a .2 shot error so for you it will max out around 400 to 425. Remember it’s going to be different from one caliber to the next
Lol. It’s really worth running. It’s just another way to engage targets for rapid target engagements. There are other options you can also look at, 12” drill and max point blank, hold over and hold under. Thing to remember they are just a tool with limitations which ever you choose. I do like the fact that I can dial down my speed drop number and make a BDC or dial the speed drop number off the distance and it gives me my D.O.P.E.
Speed drop is most advantageous with a higher BC, fast MV cartridge. 300wm with 190s, 6.5cm with 130s, 260 with 136gr ect.
You can do it with anything but the usable speed drop range I think becomes a little restrictive to get the most out of it. Still a good tool to have nonetheless.
A good example is that 223 73gr chart, if you’re working a +/-.2 error it’s effective between 150 and 400ish. So if you’re engaging in those ranges it’s worthwhile. But for instance 300wm w 190s at my DA calc’d from 250-900.. could be a little off but in that ball park. That’s a nice window for shooting larger targets. By far the biggest advantage is night engagements, where you will not need to reference a dope card or use kestrel backlight. The shooter can do the quick reduction and shoot the target quickly.
You can do it with anything but the usable speed drop range I think becomes a little restrictive to get the most out of it. Still a good tool to have nonetheless.
A good example is that 223 73gr chart, if you’re working a +/-.2 error it’s effective between 150 and 400ish. So if you’re engaging in those ranges it’s worthwhile. But for instance 300wm w 190s at my DA calc’d from 250-900.. could be a little off but in that ball park. That’s a nice window for shooting larger targets. By far the biggest advantage is night engagements, where you will not need to reference a dope card or use kestrel backlight. The shooter can do the quick reduction and shoot the target quickly.
When Ted came and stayed with me, we recorded a podcast and covered the speed drop amongst other things. I am not a numbers guy so naturally, it didnt immediately "click" in my head but i finally somewhat understood. To some people, numbers and formulas just make sense and these things become easy. For others like myself, we have to stare at shit for a long time before the already dim light bulb decides to turn on. I could see this proving very useful in a hunting scenario for sure.
I think Ted changing the direction of the adjustment is the key factor here,
By reversing it as he does, you can do both, hold or dial the same way. Yes, you have limitations, but those limitations are within a set of parameters that make sense. Going outside those parameters, in this case, is pretty obvious
Originally it was meant to work with the confines of the reticle, so you had to Dial Under, and it was sold that way, hence the change from NF to Leupold put a wrench in the works. The idea was to adjust under and use the reticle, if you follow Ted's method and go above you can do it both ways much easier to include scopes with a pre-Set zero stop.
By reversing it as he does, you can do both, hold or dial the same way. Yes, you have limitations, but those limitations are within a set of parameters that make sense. Going outside those parameters, in this case, is pretty obvious
Originally it was meant to work with the confines of the reticle, so you had to Dial Under, and it was sold that way, hence the change from NF to Leupold put a wrench in the works. The idea was to adjust under and use the reticle, if you follow Ted's method and go above you can do it both ways much easier to include scopes with a pre-Set zero stop.
Every scope should have a tool less zero but a zero stop that can be set to anything.
I shot an NRL Hunter match this weekend using this system. it was AMAZING! and FAST! And I never missed a target from elevation issues.
Here is the post if the after action report.
https://www.snipershide.com/shooting/threads/holly-smokes-that-really-worked-speed-drop.7122555/
Here is the post if the after action report.
https://www.snipershide.com/shooting/threads/holly-smokes-that-really-worked-speed-drop.7122555/
Every defensive handgun should be a glock, and all glocks should be 9mm.
Fitness for purpose. I get your sentiment, but not everyone is willing to pay $2k+ for a scope.
I have a 500$ Midas, a 1000$ Cronus and a 2200$ Leica PRS. I can set the zero stop exactly where I want on all of them. I can live with a slot to remove the cap but I think the Leica figured it out with tool less turret removal and stow a small Allen key in the windage to change the zero stop if desired.
Tried using the speed drop factor my last range trip, it worked excepionally well for me out to 6-700 with my 308 loads. Made some charts to compare my prime numbers at different DA’s and found for my load i get a .1 chnger ever 4k ft of DA. Pretty good flexibility for DA variation
Hey Ted, does your speed drop Excel chart have the formulas built in? If so, would you be willing to share it with us? Also, do you think it is worth making speed drop charts to find the various prime numbers associated with DA changes?
Yes. the google sheet has the formulas built into them. ( sorry not in excel) Link to google sheet
Fill in the front page drop data and the speed drop tab will automatically calculate your values.
Yes, DA will effect your data speed number. Come read this thread where I wrote about using the system at a match. (post 23 and 24 about DA changes)
https://www.snipershide.com/shooting/threads/holly-smokes-that-really-worked-speed-drop.7122555/
I would not change DA for minor swings or temp or pressure, but if you're traveling it would be warranted. since there is already error in the system a little more probably won't hurt. I'd look for a minimum of 2000 DA change before I adjusted.
Released in Strelok Pro for Android v.6.6.4
Released in Strelok Pro for iOS v.6.81
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I had no idea you were on here. I appreciate your efforts on your app, been using it for years and have sent you several subtension maps that you have quickly published. Thank you.
Hi there to all!! New to the forum, and still trying to figure stuff out... Does the speed drop work with both FFP and SFP, or just FFP??? Also, how do l fill out my forum profile thingy?? Ol fart here from Melbourne, Australia... P.S. nice to meet everyone.... cheers....
If you are dialing; focal plane doesn't matter. If using the reticle BDC method you'll need to be at maximum power for a SFP.
