Basic rule for rifle windage calls

[J.Boyette]

rules of thumb are just that, a way to give a great guess to a situation. Most will dispel any of these old school ways and not accurate and so on. But its a great starting point for anyone that has nothing to go off of.

The rule I like to start out with is the old WW1 rule with the 1903 Springfields. Its simple and basic:

Range of target in hundreds of yards X mph of the wind / 10 = MOA

how this works looks like this:

400 x 5 mph / 10 = MOA ( 4 x 5 / 10) = 2 MOA

now if you use a MILRAD reticle to do holds divide the MOA by 5 and you will get the number for the hold.

So the Mil math will look like this

400 x 5 mph / 10 = 2 / 5 = .4 MIL hold

Or

R = range ( in hundreds)

V = wind speed

M = MOA

MI = MIL

R x V

-------- = M

  10

R x V

-------- = M / 5 = MIL

  10

Now this is a rule of thumb and is not 100% on the money. But its VERY close.

Hope that helps some

[TacBlade]

What do you suggest with a regual Duplex reticle? For Windage and holdovers?  This is kind of a basic question, but I am looking for some insight?  What would you do for someone that shows up at your school with one of these reticles? Thanks

[J.Boyette]

TacBlade,

Great question,

What I do is place a yd stick at 50yds and measure distance from the thick stadia mark to thick stadia mark. Then from the point of aim to the thicker stadia again.

Do all of these 8 measurements and  write down the inches. Then double the inch number. This is now the MOA holds, and ranging points for that duplex.

So you might have 9" from POA to stadia thick mark. Well half is 4.5" so now you got two hold points 4.5 and 9

Thats better then nothing. I still use the same math above, just drop off the MIL stuff.

Have a good one.

[SWshooter]

I'll give a couple basic rules I've learned the hard way over the years. These are mostly for new shooters who don't have much experience in the field. Sight your rifle in for the longest point blank range possible with the cartridge and sight system your using. Generally this is no more than 3" high at midrange and 3" low at your maximum point blank range. Point blank is the farthest distance you can hit a target with out holding off or adjusting your sights. With the 308 and 223 this is close to a 200 yd zero. This will give about a 250 yd point blank range. When shooting at unknown ranges, don't hold off the target. More people miss high by over estimating range than hit low by under estimating range. When shooting at moving targets, holding on the leading edge will usually put a round somewhere on the target. Once you have established a zero, never adjust your scope in the field. You are better off holding off rather than trying to adjust clicks on your scope, if you lose your zero in the field you are in deep doo doo ( thats  a military technical expression). Don't use target turrets in the field unless they have positive locks on them. If you have a BDC, check it often, they have a way of always being set to the wrong range. Ditto focus knobs. Target scopes don't make good field scopes, too often you just don't have time to diddle with a scope when a target presents itself. Most fixed focus hunting scopes have a much greater depth of field than either a target scope or a hunting scope with a parallax adjustment. Always keep your scope on the lowest power. Surprise close range targets need to be engaged as fast as possible, surprise long range targets will usually allow time to make scope adjustments, especially if you see them first. Always move tactically (see them first). How do you know if your moving tactically? If your eyes can't cover the terrain as fast as your moving, you are moving too fast. This rule will kill a lot of deer, most hunters walk way too fast. Those are my basic rules, i'd like to hear from anyone else who has some good rules, or has good reasons for disagreeing with mine.

[Matt.Cross]

rules of thumb are just that, a way to give a great guess to a situation. Most will dispel any of these old school ways and not accurate and so on. But its a great starting point for anyone that has nothing to go off of.

Now this is a rule of thumb and is not 100% on the money. But its VERY close.

Hope that helps some

All I can say is "WOW!"... You've made wind calls make more sense in this one post than I've been able to make out of browsing all the 'pro' sites put together. I acknowledge that you aren't setting it in stone, but man it's great to even be roughly in the ballpark here. Thanks!

[J.Boyette]

Matt,

This info is not new. This formula is well over 100 years old. Its just people want to go with the latest and greatest, but forgetting how to execute with out the PDA or a wind chart.

I strongly believe in memorization on alot of stuff, then I can roll lighter with my rifle. All I need is me, rifle, sighting system and ammo. And it will work out.   

[SWshooter]

We always seem to come back to KISS, don't we?

[J.Boyette]

We always seem to come back to KISS, don't we?

Only the ones that understand the task.

As the old saying goes

Amateurs talk about hardware, Professionals talk about software.

That applies in this situation also I feel..