22lr Speed drop Factor.

[Gleedus]

I have a thing for quick intuitive ways to manage data. The Speed drop factor is one of these that along with your wind number can be very fast and effective. But what about 22lr?
If we look at CF it works out nicely with each additional 100 yards adding 1 mil of drop but we all know 22lr is.... well slightly more. If we scale 22lr and CF trajectories its ×4-6 depending on CF cartridge used. E.g. 100 yards with my 22lr is the equivalent of 600 with one of my 6mm.
Our Speed drop factor formula is YARDS/100-DROP= FACTOR. Well if a 22lr is approximately ×5 then 20 yards would be the equivalent of 100 CF yards. Lets try YARDS/20-DROP= FACTOR like this!

Hey it kinda works! But does it pan out in real life? The math is not quite as intuitive but still very simple. Your dialing 1 mil for every 20 yards. In this example I will use 3.4 as my factor by slipping my turret to 3.4 mil and now dialing down to zero again. Now I dial my YARDS/20. E.g 160yd = 8 mil or 188yds = 9.4 because our minds find dividing by 2 easy just take the first 2 digits / 2 and then add a 0.1 for every 2 yards in our last digit.

Because 22lr all have very simular drop there is a simple shortcut to identify your Speed Drop Factor. Take 160yds/20-Drop-0.1. In our example
160/20= 8- 4.5mil= 3.5-0.1=3.4
This is a environmentally effected number so be sure to calculate it with your current conditions.
Now this begs the question if the Speed Drop Factor works what about a BDC? Absolutely it does. It runs along the same lines but here is the quick answer. Take 5- your speed drop factor. In our example 5-3.4=1.6 Dial up from your actual true zero (does NOT have to be 50) 1.6 mil or if you have slipped your turret to your speed drop factor already just dial up to 5 at first glance this appears to coincide with your 100 yard drop but this is not the case and will not work. Anyhow this is how it would look at two different temp with our example ammo.
20⁰c

30⁰c

Here Is another example with different ammo.

This is based on usefulness for a 22lr UKD distance field match where the majority of targets run from 100-200 yards.
Some ammo you will need to start adding additional 0.1mil per 10yds at 180yds. With a bit of thought you can expand on this. But I'll leave that to you.
If your wanting something useful for hunting or 50-120 yds thats also possible but another conversation.
Anyhow I think thats it in a nutshell. Cheers

 

[Leatherlunger]

Cool stuff dude just found this thread

 

[Keeper22]

Good stuff

 

[DFOOSKING]

Problem I see, is the data changing during the day let alone the week on shots over 100yds. I wonder how flexible it will be with something that has 0.3 to 0.5 mil jumps per 10yds.

And yeah, obviously your making concessions in the given sight setting versus the actual needed sight setting.....but will the targets we shoot be big enough to allow it that error?

Time will tell.

Personally, I think shooters need to know what their .22's trend in rougher increments out to say 200yds. Like any hard-core CF shooter knows off the cuff what their dope is in 100yd increments in generality.

If we know the 25yd increments like that....

50- 0
75- .9
100- 1.9
125- 2.5
150- 4
175- 5.2
200- 7


And then come up with a rule of thumb for the yardages in between. Like every 5 yards is 0.3 for example.

Most shooters know what they trend at 100yds. 2.0 mils in the winter. 1.8 mils in the summer.

Just saying maybe their is a easier way.

I doubt it because my local wind is killer. The day most people shot in a 30mph was the craziest day of their life. But for me it was Tuesday.

If I'm having problems...it's the wind speed and angle and the awkward ways our local range funnels it. And if your elevation is varying....it means the wind is too. The speed factor is gonna have a hard time dealing with that I think.

Look forward to what you come up with.

 

[Gleedus]

Problem I see, is the data changing during the day let alone the week on shots over 100yds. I wonder how flexible it will be with something that has 0.3 to 0.5 mil jumps per 10yds.

And yeah, obviously your making concessions in the given sight setting versus the actual needed sight setting.....but will the targets we shoot be big enough to allow it that error?

Time will tell.

Personally, I think shooters need to know what their .22's trend in rougher increments out to say 200yds. Like any hard-core CF shooter knows off the cuff what their dope is in 100yd increments in generality.

If we know the 25yd increments like that....

50- 0
75- .9
100- 1.9
125- 2.5
150- 4
175- 5.2
200- 7


And then come up with a rule of thumb for the yardages in between. Like every 5 yards is 0.3 for example.

Most shooters know what they trend at 100yds. 2.0 mils in the winter. 1.8 mils in the summer.

Just saying maybe their is a easier way.

I doubt it because my local wind is killer. The day most people shot in a 30mph was the craziest day of their life. But for me it was Tuesday.

If I'm having problems...it's the wind speed and angle and the awkward ways our local range funnels it. And if your elevation is varying....it means the wind is too. The speed factor is gonna have a hard time dealing with that I think.

Look forward to what you come up with.

It definitely does change over a day. You have to change your SDF through out the day. But the same thing applies. My SDF changes 0.3 mil max with the Eley I run. So very simple to account for.
Memorizing drop is a way that can work too but you still have the effects of environmentals to remember to add or subtract.
There is another method you can use that works well by adding or subtracting yardage based on a significant of environment change. You then run a BDC turret wrap. Both methods work better then memory on the clock.
All methods work better in CF just because of the apparent forgiveness of trajectory. Memorizing every 100 yards of my 6mm to have the same resolution with my 22lr requires memorizing in 15 yd increments.
In either case its gear towards larger targets of a hunter style match where you need to range. not PRS with targets in the low 10ths.

Wind can also be done very simply mentally with a 22 as well I'd say easier then CF but RF is my main matchs. The biggest thing is if a person know what all the effects can be.