[mm1ut1]

How far will a 20 mph crosswind push a 69 gr SMK out of a 20" AR at 100 yards? Thanks!

[Larry Burchfield]

I think you can figure this out if you the muzzle velocity of you round that you are shooting and have one of those programs but the MV is important to know.:)
Larry Burchfield
SEABEES/VIETNAM/67/68/69
DAV

[mm1ut1]

I don't have a chrono, but they were loaded with 25.7 gr of Varget. Reason I ask is that I shot in a league service rifle match yesterday under those conditions and a lot of people shot poorly. Since we were shooting at 100 yards with reduced targets I think the effects of the wind were minimal. The winds were between 90 degree and 45 degree (shifting) and 20-25 mph.

[Larry Burchfield]

I shoot a 223 700vs remington with a bull barrel and 52 grain bullets and I get some drift at 100 yds. I think that with the wind blow like you describe you could get as much as a 1/4 inch or better.
If you have a loading manual this can be figured out or close to being figured out by guessing the MV. The MV will be different with the load if shot in 2 different guns.
A gust of wind can blow the bullet more. If the range will let you put up wind flags to help read what the wind is doing. If the tail is straingt out don't shoot unless you are running out of time. You want to shoot just as the tail begins to fall back to calm.:)
Larry Burchfield
SEABEES/VIETNAM/67/68/69
DAV

[Jim Watson]

Assuming the 69 gr SMK at 2700 fps in a 20mph crosswind at 100 yards, the drift is 2.29 inches, per Sierra Infinity ballistics. That is a lot on the reduced target.

[dardascastbullets]

The effects of the wind had more of an effect on position(s) than the bullets by far. 20-25 mph winds at the side can affect those who are not prepared for such conditions. I had two positions - calm days and rough days - and was very successful. Do not be concerned with the insignificant movement of the bullet at 100 yards and work on obtaining positions that will be better than your competitors. Your improved groups will show your efforts.

Matt