DEW POINT

[Troy Bakel]

I have completed 7 Night Precision Benchrest shoots with the last 5 shoots starting above dew point then falling to/below dew point.

Equipment:

Rifle: <12FPE, 0.177, Piatt tuned Thomas BR
Rest: PQP Lite with roller top
Target: 2013 to 2021 ERABSF 25 Meter set at 82'
Vane: anemoscope with VHS tape telltale

Observations:

1. Foulers and sighters are shot at 2030 with temperature at 90+°F : and above dew point. POA-POI & Dispersion have been normal - wind has been very, very , lite on these hot evenings which is why I have been using VHS Tape as a telltale.

2. Record shots begin shortly after 2100 when target Illumination becomes effective.

3. As the air temperature drops the telltale will just hang as the air goes still.

4. When the dew point is reached the telltale will begin to vibrate, first at its bottom "free" tip then slowly along its whole length. I think this is caused by the latent heat of condensation rising from the grass as the water vapor condenses into dew.

5. When the telltale is vibrating along its full length the pellets start to form vapor trails on their way to the target. Once the vapor trails begin, my 10's go way, way, soft and my 9's go way hard. The pellet hits will move around the 9 ring in both clockwise and counter clockwise directions. This will continue until the air starts moving enough to raise the telltale.

Is what I observe due to Diabolo External Ballistics in vapor saturated air along with thermal gradients created by the latent heat of condensation rising up through the super saturated air column?

Or just another LSD Flashback?!?

 

[Gerry52]

I'm voting for the acid flashback. You be "halutinatin'" them vapor trails

 

[Ricochet]

Glad to see I'm not the only one having hell trying to land x's in hot dead wet air. Hope you get it figured. I've put a fan on my gun when i sit it in the Randolph, if i don't the glass sweats. Gun is 70 degrees, and the inside of my shooting shed is about 120 when i open the doors. Without the fan, the gun will start dripping condensation like a glass of tea.

 

[RoosterCogburn]

Simple. A psilocybe cyanscens/ballistol tincture to lubricate the extraconcious psychoballistic performance of the pellets. And yourself, I suggest the Hoffman/leary method. Sans ballistol

 

[JEFFPPC]

Glad to see I'm not the only one having hell trying to land x's in hot dead wet air. Hope you get it figured. I've put a fan on my gun when i sit it in the Randolph, if i don't the glass sweats. Gun is 70 degrees, and the inside of my shooting shed is about 120 when i open the doors. Without the fan, the gun will start dripping condensation like a glass of tea.

When the warm and cooler air come together you create mirage. Set the gun up, don't touch it and you can watch your bullseye move around, Not. You created an optical illusion. Plus shooting in wet air or heavy air will slow your projectile down possibly affecting both velocity and point of aim. Learning to stay on top of these conditions separates the top of the list from all the rest when results are known. The longer you stare at it the worse you will shoot in my experience. Your brain tells you your target moved......Your brain has been tricked. It gets even tougher when your flags and the mirage you view don't agree.

 

[nomojo65]

I’m assuming dropping into the “dew point” zone can happen at any given temperature/moisture condition? When these conditions are present as the air compresses around the front of the pellet the condensation can be forced out of the air then re-vaporized at the LP zone at the back of
the pellet? I’m assuming this can lead to destabilization?. A slow speed “12fb gun should be more stable in these conditions?. Assuming there is enough residual heat in the ground, a few inches to a foot or more could keep the atmosphere in the vaporization zone? “Shoot low” As far as mirage this is where some wind is your friend! Otherwise you have to wait for the boil to snap, fun,fun!