Mph gun for 22?

[Jesse_L_B]

hi guys, i have been reading about the mph gun wind method. How do I correlate that to 22lr? I seem to struggle with the wind and a friend of mine pointed me to the mph gun thread. I understand the concept, i just don't know how to put it in practice with a 22. Here is a pic of my cz 457mtr in a krg bravo topped with a gen 2 viper.

 

[JBoomhauer]

I personally would just get the wind value for 1mil @ 100 yards, just to make the math easier. To match my centerfire drop @1000 would be somewhere arouNd 215 yards. That number is a bit harder to work with on the fly.

 

[Jesse_L_B]

I personally would just get the wind value for 1mil @ 100 yards, just to make the math easier. To match my centerfire drop @1000 would be somewhere arouNd 215 yards. That number is a bit harder to work with on the fly.

That makes sense. Thanks for helping me out man. I appreciate it

 

[LV Precision]

I used 100 yards as the baseline for my Tikka T1x, with CCI SV I have a 10 mph gun.

 

[Powder_Burns]

Can’t remember quite well, but it was something along the lines of .1 mil per 10 yards. Play with your crosswind value in the ballistic calculator until that lines up. For me it was 7mph.

 

[LV Precision]

I used 100 yards as the baseline for my Tikka T1x, with CCI SV I have a 10 mph gun.

I pretty much dont shoot anything closer than 100 yards with my 22; at 10mph, every mile per hour changes my windage by .1mil.

 

[Shootin Stuff]

Have a play around with your ballistic calculator until something sort of lines up, it shouldn’t take long to find a number that works (ish), 20-25yd increments is likely where you will end up and you might not see a trend until past 50 yards or so.

You will probably find that a crosswind from the left requires a greater hold than from the right, so you can just split the numbers to get close and SWAG the difference or make a final correction based on actual POI on target.

And don’t forget your AJ correction either, it does noticeably change your vertical POI. A few things you can effectively ignore with CF move that little 22lr around at distance.

For practise wind reading, just take your weather meter wherever you go outside to the mailbox, walking to/from the car etc. Stop for a second, guess the wind and confirm with your meter. It wont take long to get better at it.

 

[Jesse_L_B]

Ok guys I think I got it. So i used 400 yards and to get 4 mil correction I was at 10.5mph
I used 400 because I shoot out past 300 as much as I can, I really qant to hit 500 or better this summer with my 22. Now my wind was coming from 3 o'clock. How will I adjust for quartering to and away winds? When I first ran the numbers I did it at 100 and came up with a 9 mph value. Am I better to use the 100 yard or 400 yard info? Thanks for taking the time to help me get this all figured out.

 

[JBoomhauer]

That is prob about as good as you are going to get with the mph method. It is supposed to be a quick reference, so a 9.8 mph gun would generally be rounded up to a 10mph gun knowing that estimating wind over 400 yards is imperfect. If you plan on shooting closer to 400 use that number if closer to 100 use that.

 

[Shootin Stuff]

Ok guys I think I got it. So i used 400 yards and to get 4 mil correction I was at 10.5mph
I used 400 because I shoot out past 300 as much as I can, I really qant to hit 500 or better this summer with my 22. Now my wind was coming from 3 o'clock. How will I adjust for quartering to and away winds? When I first ran the numbers I did it at 100 and came up with a 9 mph value. Am I better to use the 100 yard or 400 yard info? Thanks for taking the time to help me get this all figured out.

What ammo are you shooting? At 500, you want a tight MV spread and GOOD atmospheric data.

The mph method is a quick and dirty rule of thumb that is easy to remember, works well enough (for CF) and gets you close in reasonable wind out to 800 yards or so, it is not (and not intended to be) a replacement for good ballistic software and real world DOPE.

500m with 22lr is beyond any sort of useful rule of thumb accuracy window and there are too many variables working on that slow draggy projectile that can not be ignored.
To get any kind of consistency on a day in day out basis under variable atmospheric conditions you really need to be using a ballistic calculator and weather meter.

Sure you can SWAG it close and walk it on from there, but why not take advantage of the tech and use some science to get you on target sooner? Trying to make every round count, even if it is “just a 22” will pay off in the long run if you want to start stretching CF in future as well.

Don’t get me wrong, the MPH rule is an AWESOME shortcut for wind holds. Your application and end goals are just way beyond its useful range.

 

[Shootin Stuff]

For your quartering head/tail wind question, there are a lot of different “wind rose” type rules of thumb.
Once again though, they are all rule of thumb to get you close enough with CF. In your particular application, rules of thumb and a wind rose will result in a lot of misses.

You need accurate data.

 

[PAYDIRT]

I get it but I don't get it, hopefully the mph thing fades fast

 

[Rumblingdwarf]

I have used .1 mil per Mph of wind at 100 yards with good success. 5mph = .5 mil hold.

At 50 yards you can cut that value in half. 5mph = .25mil hold.

At 200 yards you can double it.
5mph = 1.0mil hold ect...

This is quick and dirty to help get close, if not on target and you can fine tune adjustments from there.

 

[rybe390]

I will mirror what others have said. You can use the mph method with .22lr, but you refine your "hundreds of yards" a bit further to include the nearest 10 yards.

50 yards = 0.5
150 yards = 1.5
5 mph = 0.5
15 mph = 1.5

Mph times hundreds of yards including tens = total hold

5 mph x 1.2 = 0.6

1 mph = .1 @ 100 yards
1 mph = .2@ 200 yards
10 mph = 1.0@ 100 yards
10 mph = 0.5 @ 50 yards
10 mph = 1.8@ 180 yards