Home Forums Hunting & Shooting Long Range Hunting Horizontal stringing

A wind from 11:00, 1:00, 7:00 or 5:00 is 30 degrees off so crosswind effect would be half that of the same wind from 3:00 or 9:00.

Biggest effect I've experienced on causing lateral (horizontal stringing) off the bench is not having the rifle fore-end centered in the front rest, causing intermittent horizontal stringing.

Ed

😀😀😀

What time of day did you shoot? If the sun was out with a slight breeze mirage would open up the group. If it's a known load your shooting I would lean toward you were getting a weather report instead of a load report! Other causes would be seating depth, rifle needs cleaned, scope giving up, your not a good shot, etc

Maybe the gravity wasn’t Continuously pulling the same during your shooting session, fluctuations can cause vertical strings.

While the parabolic natural log calculations have merit, a much larger effect on vertical dispersion is the vertical wonkiness factor or VWF. When it approaches infinity the rotational portion of projectile repeatability increases exponentially, and may have influenced the results observed by the shooter at 300 yards. To complicate matters, the VWF and HWF (horizontal wonkiness factor) interactionally inversely influence each other, forming the total tangential wonkiness factor, TTWF. When TTWF approaches 1.0000000 use extreme caution as point of impact could be almost anywhere, and the group size approaches infinity.

Another force may be in play here as well; the trigger spring twanger tension, TSTT. It can be influenced by any number of things such as the change in density, viscosity, shear force etc. of the lubrication in the mechanism, relative expansion/contraction in the steel, aluminum, plastic parts, and more. All of these are sensitive to temperature, pressure, dew point, phase of the moon, velocity of the trigger pull, and general wiggling around on the bench. A simple example of this is flicking a booger off your finger (the spring twanger) where the viscosity and stickiness can dictate success or failure to launch the projectile in a particular direction and hit the target in the intended location. Groups....forget it! Especially without a good rest.

The math involved in the calculations is expansive, and would have given Albert Einstein indigestion or worse. Where is Stephen Hawking when we need him most?

My math is VWF + HWF + TTWF + TSTT = 100% BS

Good One!

Horizontal is tuned out with seating depth during load development. Seat the bullet in .005 increments away from the lands until you see the load go horizontal and then you’ve went too far. If it’s factory ammo, nothing you can do without a barrel tuner. It can be trigger puller induced also which would be the first thing to try and rule out.

It may help to sacrifice a small animal, like a rabbit or a chicken, to the gods of horizontal dispersion. Works for me. I sacrifice hundreds of small animals a year.

^^^This!^^^

I had the same problem with a 7mmRM last year. Great groups vertically but pretty much two separate groups, separated horizontally. Anyway, somebody on some form said that adjusting the seating depth should correct it and it went from 1.5MOA to 0.5MOA.

Yes, air masses of differing temperatures seeking equilibrium. During the day, air above land heats up faster than air above water. Warm air above land expands and rises, and heavier, cooler air rushes in to take its place, creating wind. At night, the winds are reversed because air cools more rapidly over land than it does over water.

Yall are funny. Coriolis and 300 yard groups. 2 inches? Lol. Nut loose behind the trigger. 2 inch group at 300, I'm happy, lmao.

What Ernie and onebackcast said,I might add that environmental issues are a major variable in the group size as is the shooters ability to read such........

The shooter. You weren`t shooting the conditions, but just shooting.

Good example of Horizontal springing. Notice the wind direction.

On serious note. Is Vertical stringing is due to powder charge?

Mostly blamed on velocity variation, which can be due to several effects. Charge, cartridge neck issues, inconsistent OAL.

For once i think you might have nailed it Ernie. lol