Real bad heat mirage

[7ultra]

I was shooting on the 100 yard line this past sunday, temp was around 45 (which is real warm, compared to earlier weeks). Anyways, I was shooting my 6.5, which has a Weaver T-36 on top. The heat mirage was so bad, I could barely get a bead on the target. I don't remember ever having this problem during the summer, so I'm at a loss. Could it have something to do with the sun/warm weather and the still frozen ground? I noticed slight mirage with my 8x Leopold(edit: it was barely noticeable, not even a problem), but it was horrible with my 36X scope. Any thoughts?

 

[royinidaho]

My explanation is that mirage is caused by the temp difference between the surface and the air above it. The greater the difference the more the mirage. This explanation works for me during the summer here in Idaho.

However, I haven't figured out what the deal is in the winter. Mirage is as bad as in the summer, at times.

36X is pretty much useless with heavy mirage. When I was shooting a 26 Leupold on a 222 40X @ 100 & 200 it gave me fits in the afternoon. About 10X maybe 16X is as about as much when mirage is running.

HTH, at least a little bit.

 

[abinok]

Roy hit the nail on the head.
Its not the temp, its how much the sun heats the ground.
I shot back in December, 20 degrees, then the sun came out. My 5" of black bullseye at 400yds flat disappeared. Wild stuff, but it happens!

 

[Gerald89]

I read somwhere that heat from the barrel can cause a mirage that makes the sight picture appear to move?

Jeza

 

[preacherman]

...you're correct ...often in benchrest you'll notice "shields" attached to the barrels to prevent mirage in front of high magnification scopes...

 

[7ultra]

As said, you are correct, but it would take quite a few shots to warm up the Lilja that bad.