Feel free to move this if this isn't the right forum.

I took my M&P15-22 out the other day to try out a new scope. I was at 100 yards using CCI Blazer 40g LRN. The wind was 17-26 with gusts to 34. Would the speed of the wind affect shooting this caliber ammunition and how far "off" would the bullet be from where I was aiming.

I was also shooting .223 that day. Ammunition was 55g Wolf Gold. Would the wind speed affect this caliber and how "off" would the bullet be from where I aimed.

I am NOT an expert in ballistics, etc. I'm basically at the level of "bullets for dummies."

Yes the wind will have an effect on the bullet. And the direction of the wind will have the most effect. Deal with it all the time where I am where 15-20mph wind is a nice light breeze.

About how fast does the wind have to be to really effect the bullet?

Reading the wind is an art.

Wind like that will blow 22lr all over the place at 100yards at least a few inches maybe more. It will move the 223 as well but not nearly as much as the .22lr.

Wind direction is huge as well. Head and tailwinds will have minimal effect at 100 but crosswinds can give you problems.

How far off would you estimate a .223 be in this wind?

Wind will effect any projectile. The ultimate questions are:

How long is the wind affecting the projectile?
Which direction is the wind blowing?
How fast is the wind?

How long the wind is affecting the projectile is dependent on range and velocity of the projectile. A 5.56 at point blank range won't have any discernible impact, where a .45 at 100 yards will.

The direction and velocity of the wind should be fairly self explanatory, but at real long range the direction and speed can change during the travel path.

Truly adjusting for wind is as much art as science. This is why long-distance shooters log each shot and the applicable information about it.

Read up here:  http://www.millettsights.com/resources/shooting-tips/shooting-in-the-wind/

Thank you for the information. Looks like I have a bit of reading to do.

At what MPH does wind affect a .223 FMJ?

Any speed of wind will affect any projectile. Again, it's the amount of time exposed to the wind (factors of range and projectile velocity) and the velocity and direction of the wind that will determine how much.

Perhaps you need to actually ask the question you want to ask, which I suspect is something like, "will a 10mph crosswind make my shots land 4" off at 50 yards?"