What weather conditions do you record?

[K9TXS]

Doing quite a bit of reading on weather conditions and rimfire benchrest shooting. Some shooters record much more than others. However, I'm only curious about rimfire at 50 yards.

I've been to quite a few matches and I usually get there early and there are quite a few shooters that have their Kestrels out taking readings and then looking over their notes.

I asked one fellow a few questionst, but he didn't want to talk about it. He wasn't rude, just didn't want to talk about his notes. Funny though, when I saw him later and talked about his rifle and other items, he was very open. So, I asked a question about the effect of barometric pressure on the flight of the bullet. He smiled and did not answer.

What are serious shooters looking for before changing from one ammunition FPS to maybe the same brand of ammunition but different FPS. I've seen some shooters recording;

1. barometric pressure

2. relative humidity

3. temperature

4. wind speed

5. wind direction

The ones I listed seen to be pretty general what I've seen.
Can anyone add to the list?

 

[...]

at 50yds.......none.

at 100yds.....none.

ive been shooting at the national matches for years, and am a master class shooter........

i find a good lot of ammo...buy a much as i can...and shoot that lot until i run out.....at which point i clean the barrel and start the whole BS over again.

ive shot in blistering heat.......pouring rain.......never had my zero change by any appreciable amount.


if you have the option to check and adjust your zero.....there is really no need to record much of anything.

 

[woogie_man]

Depends on where you live. Personally shooting at temps from 90°+ down to -30°f will cause some change, even at 50 yards you will see some change.

Typically I keep a record of temp, humidity if possible, and of course wind.

 

[straightshooter1]

I'm not a competition shooter and just someone who's skewed towards the physics aspects of shooting. So, I'm very often recording data when I go out an shoot. I find wind speed and direction to be the biggest exterior influence . . . even when shooting at 50 yds. Otherwise, it's mostly in the ammo you use and like mcameron said above, finding a good lot of ammo (really good match grade ammo) is huge getting low ES's and consistency within various conditions. In Physics, we know that increasing speed increases mass . . .so, at these low sub sonic velocities things like relative humidity isn't going to have much effect like one would see on much higher velocity bullets. Let your cartridges bake is the sun before firing it in your rifle will surely affect your POI relative to much cooler cartridges. Just how much difference one might see in a 22LR cartridge, I can't say . . . but it may not be near as much as one may think in terms of heat's effects on much larger powder charged cartridges.

 

[TheGerman]

Doing quite a bit of reading on weather conditions and rimfire benchrest shooting. Some shooters record much more than others. However, I'm only curious about rimfire at 50 yards.

I've been to quite a few matches and I usually get there early and there are quite a few shooters that have their Kestrels out taking readings and then looking over their notes.

I asked one fellow a few questionst, but he didn't want to talk about it. He wasn't rude, just didn't want to talk about his notes. Funny though, when I saw him later and talked about his rifle and other items, he was very open. So, I asked a question about the effect of barometric pressure on the flight of the bullet. He smiled and did not answer.

What are serious shooters looking for before changing from one ammunition FPS to maybe the same brand of ammunition but different FPS. I've seen some shooters recording;

1. barometric pressure

2. relative humidity

3. temperature

4. wind speed

5. wind direction

The ones I listed seen to be pretty general what I've seen.
Can anyone add to the list?

Density altitude and temperature is what you need.

Find a round/lot that your rifle likes

Chronograph that round. The more temperatures you can chrono the round at to see what temperature does to the velocity is helpful.

Use JBM or a ballistics app to make density altitude range cards. I do it in DA steps of 2k and 60/80/100/120 temps.

Zero at X temp and Y density altitude

Make all of your DA/temp cards adjust off of the X temp and Y DA, zero.

For example, today I went and warmed up with my 22LR at 100y before shooting my Barrett MRAD. I focus on first round hits, so I pulled my DA cards for my 22LR/ammo combo out and I ran my Kestrel for a bit. I'm zero'd at 80 degrees and 4000DA; today it was in the 6000s as far as DA and temps were 100-105 so I used my 6k DA card and referenced the 100 degree portion of it.

Saw that for a 100y shot, the zero had changed .2MIL at 100 yards. Adjusted the turret and shot, and was right on the 3/4 inch sticker.

 

[Snuby642]

I think 22lr spazzes out worse in the colder temps.
My 22s like it hot.
Me not so much. Lol