How windy is too windy to zero a scope?

[radshooter]

I was planning on going out this afternoon to zero my new scope on my new rifle, but we are getting a bit of breeze today.

Wind is 10 -15 mph. If it is blowing the same direction at the range as it is here at the house, it will be a full value cross wind.

Rifle is a Bushmaster LR 308.
Scope is a Viper Vortex PST 1-4 X 24.

Would it be worth going out? Wait for a calmer day? Zero with a bit of "fudge factor" and re-zero on a better day?

I was planning to zero at 100 yards, so not a great distance, but is it too much for the wind?

What do y'all think?

Thanks

 

[ColtPythonElite]

Any wind is too windy for me.

 

[TonyAngel]

At 100 yards the wind isn't going to make much of a difference. If it does, you won't be more than a click or two off anyway. That's a nice scope you have, BTW. I got to check one out this past weekend. I'm gonna grab one of the larger ones when they become available.

 

[joed]

I like calm but that wind doesn't sound to bad. I'd probably go just to get it close.

 

[radshooter]

Well, I went out for a bit. It was a LOT windier out there than here at the house. Good news.....it was almost straight behind me. Bad news.....it was COLD.

I only stayed long enough for twenty rounds at 25 yards, but I am real happy with what I accomplished. I am pretty well zeroed at 25 yards, so I should be pretty close at 100. I will go out again at a later date and try again when the weather is better. We put a new scope on the wife's AR15, and she wants to learn to zero it herself . She wouldn't let me take it out today!! We will go out some weekend when she is off work for that. I am happy she wants to do it herself. She is starting to learn there are targets beyond 50 yards!!!

My best 3 shot group was .232 inches at 25 yds. My worst (and first) was 1.032 inches. I can't wait to try this out at 100 yds. I was shooting off my tailgate using the range bag for front support. I think with a bit of practice, this rifle will be a real shooter.

 

[Red Cent]

"Wind Effects"

"A bullet's reaction to a wind depends very much on both the speed of the wind and the direction in which it blows. In the first place, a headwind or a tailwind causes a vertical deflection (a change in drop) of the bullet, while a crosswind causes a horizontal deflection. It also happens that a crosswind causes a much larger deflection than does a headwind or tailwind of the same speed. As an example, take the .308 Winchester cartridge loaded with the Sierra 190 grain HPBT MatchKing bullet at a muzzle velocity of 2500 fps. At a range of 600 yards, a 5 mph headwind would cause the bullet to strike the target 0.30 inch lower than it would with no wind. A 5 mph tailwind would cause the bullet to shoot high by the same amount. In either case, a well-aimed shot certainly would stay within the X-ring on the 600 yard target. But a 5 mph crosswind would deflect the bullet 14.35 inches to one side, with a devastating effect on the shooter's score if he hadn't made a windage correction."

The lighter the bullet, the more it is affected.

 

[unwise11]

Sighting in is best done at 25-50 yards, then you just shoot at 100 later and tweak elevation.

 

[JDGray]

I was planning to zero at 100 yards

Sighting in is best done at 25-50 yards, then you just shoot at 100 later and tweak elevation.

JD, How else can he get a 100yrd zero?

 

[unwise11]

I like to get dead on at 50, and then shoot a little off at 100, usually a bit low, I think because my range is a sloped piece of land, and I just move it up 1 MOA, and I can hit paper at 200, and move up for 300, no problem, a 50 yard zero is essentially a bullseye at 100 yards after 1 shot.

 

[JDGray]

Zeroing a scope at 100yrds has one meaning to me, and that is to have both my elevation, and windage turrets set at "Zero", and be dead on at 100yrds. Of course you first have to have the scope "sighted in at 100" But after that, you reset your turrets to zero. When I back up to 200yrds, I dial in 2 moa,(8 clicks on my scopes) and when I back up to 300yrds, I give it 3 more moa(12 clicks) If your scope has resetable turrets, you can zero it at any distance you want. Someday I'll have a 1000yrd range to embarrass myself at, but until that range is layed out, I only have 300yrds to shoot at.

 

[35 Whelen]

First and foremost, bookmard this page: Ballistic Calculator It's the most simple, flexible and easy to use calculator I've found.

Wind is really not that hard to deal with at 100 yds. If it's a dead ahead or behind wind, I don't worry about it. If it's a side deflecting wind, I add the deflecting value to the zero. In other words if the wind is left to right at 20 mph, and it would blow the bullet 3" to the right, then I sight the bullet to hit 3" to the right.

When I sight in for hunting, I normally sight for a point of impact of about 2.5" @ 100 yds. With most modern cartridges and bullets, this will put the point of impact at 225 -275 yds. depending on the velocity and bullet shape. Frankly, I've never understood the concept of sighting dead-on at 100 then twidling with the knobs to shoot at longer ranges. That may be fine on the range, but sounds like a sure way to miss a shot at a game animal.
35W

 

[Geno]

35 Whelen:

Wow, great link! Thanks!

Geno

 

[JDGray]

When I sight in for hunting, I normally sight for a point of impact of about 2.5" @ 100 yds. With most modern cartridges and bullets, this will put the point of impact at 225 -275 yds. depending on the velocity and bullet shape. Frankly, I've never understood the concept of sighting dead-on at 100 then twidling with the knobs to shoot at longer ranges. That may be fine on the range, but sounds like a sure way to miss a shot at a game animal.
35W

No doubt, I wouldn't dial turrets and hunt. That calculator is one I use too, print off a chart for each rifle and load