Fine Tuning @ 1300

[T3-OleMan]

Jeff, I did your Bore Tech Eliminator process after Nellie started growing in POI cause she had reached her limit on dirty bore accuracy (30+-rounds). Cleaned to the shine and 2 days later went back and Clean Cold Shot was 1.2"H & 3/4" L@ 100 yd. Moved my Zeiss 1 click R (1/3s) Cleaned it with Cu+2, cause I took wrong bottle and next Clean Cold Shot touched the Vertical! I can't shoot any better than that so I came home with Zero @200Yds and have not cleaned it yet. Guess I'll clean it or should I leave it with that perfect last shot in there. I plan on shooting 1 < 4 in CO at 8K' so should I leave it alone till hunt is over????
As always I appreciate and adopt your input.
Thanks

Now for SPIN DRIFT then CO next week!

Are these close enough for Gov. Work in my rig? Or do I start over?

Givens: For Spin Drift - SS 24 3/8" 1/10 R"
Hornady GMX (grains) 185
Ballistic Coefficient 0.42
M. Velocity (ft/s) 3,009
Sight Height (inches) 1.8"
100 Range (yds) +1.2"
Zero Range (yds) 200
Altitude (ft) 9,928
Station Pressure (hg) 20.01
Temperature (F) 19 SNOW
Humidity (%) 99


Corrections left - NO WIND:
1,000 Yds = 4"
1,100 Yds = 5"
1,200 Yds = 6.1"
1,300 Yds = 7.4"


If not please give me one number as a benchmark.. If you need more info. just ask..
Even though where I hunt I only have a 2 < 5 % chance of ever taking this shot, the ELK deserve me to know where my bullet is suppose to be at that range, under all conditions. I will be prepared!


Thanks again

 

[Broz]

T3, if your last shot was spot on I would not worry about cleaning until after the hunt. Mostly for the confidence factor.

Corrections for SD are different with every caliber and bullet. But not that much. Usually if a guy puts in 1/2 moa left from 800 to 1200 it will be closer than we can shoot within. So I say your measurements inches are good to go.

Have a great hunt!!
Jeff

 

[jackem]

T3-OleMan,

I am assuming these:

Altitude (ft) 9,928
Station Pressure (hg) 20.01
Temperature (F) 19 SNOW
Humidity (%) 99

Are conditions you are putting in for your Colorado hunt?

What unit are you hunting? I don't know how much humidity affects LR shots but 99% humidity here is rare - at 6 AM this morning, the most humid hour, we had 34% here in Grand Junction and it will be around 10-15% as the day warms. Daily temps are in the 70s and lows are around freezing.

You probably shouldn't come out here at this time of year, it'll make you want to stay

Good luck with your hunt!

Jack

 

[T3-OleMan]

Jeff,
You are a "GOOD MAN CHARLIE BROWN"!gun)
Don't care what Roy says about you.

Good luck to you and your WOOOFFS.....may they all stop to see what you are...just long enough!

Thank you SIR!

 

[COBrad]

The humidity figures jackem gave you are pretty typical for western CO. When I was setting my my G7 I was doing most of my shooting about 9 a.m. and humidity readings were around 25-27%.
I have set up both of my LR scopes with .5 moa left windage as my zero, to compensate for spin drift. It has worked well enough to shoot over a dozen marmots this year from the mid 500's to the mid 1100 yard marks adding appropriate windage and no further compensation for SD. I need to do more work on paper at 1400 to be certain, but it appears another .25 MOA for SD is needed there.

 

[T3-OleMan]

Jack, Thanks for your input.

"You probably shouldn't come out here at this time of year, it'll make you want to stay."
You are right about that. Been there 19 years in a row (counting 2012) and would move there in a skinny If~n I had the $$. If I live long enough I will be on I-40 passing through Music City about this time next Sunday and be there on Oct 16th for second rifle on Oct 20.

"What unit are you hunting?"
I hunt units 77,78,771 & back in the day, also 751. Did archery first 6 or 7 years. Love that "Three Sisters" area. It's bad ***, but beautiful! Also, don't think humidity effects LRH that much (up to 1,000 Yds.) but stuck it in cause I had it and did not know if his program called for it. Must be important or they would not have it in all ballistic calculators I have used.

lightbulbHowever, I do believe that since humidity is water in the air, a bullet will drop faster at 1 mile to 2 miles in high humidity than in the Sahara desert with < 5% H.

"Are conditions you are putting in for your Colorado hunt? "
Yes, I developed a spread sheet in 10 degree increments (rows) from 0F to 100 F with all the ingredients for 11 columns of shooting solutions in SC @ 500' and CO @ 8K', 9K', 10K' and 11K', so I have all the different conditions covered. All I can do now is SCREW it UP or have an ENDZONE CELEBRATION.

I go to the locations Weather Forecasts ( when conditions are right to capture actual conditions ) with those elevations that I want facts for and save a print screen with ALL the data on it (to input into my shooting solutions) so my projected bullet flight will be correct. A mans' got to know where his bullet is suppose to be under all given conditions.

You Assumed correctly: This is a real world snapshot!
From a saved print screen for Vail, CO_ 26 Oct 2011{i.e. Leadville (KLXV) Weather Station}
Altitude (ft) 9,928
Station Pressure (hg) 20.70 {my bad-corrected for fat finger mistake on Bar Pressure 30.02in. conversion}
Temperature (F) 19 SNOW {Was 13F to 36F that day}
Humidity (%) 99 {Was 82% to 100% that day-I picked 99% so a 1 did not appear on report.}

You are at Grand Junction where the weather station is at 4,859' so it don't help me much with station pressures, temperatures & humidity. I am old school and if it is a light Snow and Misting it is going to be 100% Humidity in my book no mater what some "Gubment" worker says. Here is what I am talking about LOL.

"Denver REPORTS_6,249'_10:01AM MST_28 Feb 2012_34.7F_Bar Pressure 29.54IN_Light SNOW and Mist_Humidity 57%".

You may not be old enough to remember this or was not in the area back in Oct. 10th (+-) 20th 1994, But it snowed 4' over 5 solid days in or about that time period over on Turkey Creek in unit 78 and 2 brothers died cause they let their tent cave in on them and sleeping bags got wet. It sticks in my mind cause I did my first Elk Archery hunt last week of August and first week of September that year just a couple of Mountains over from there. Read about it in Fields & Streams the next Summer I think. and I have a healthy fear of anything close to Zero F and 100% humidity at 10,000' and don't want to mess with it, but if I get trapped in it I will be able to shoot in it, unless "I've fallen and can't get up" LOL!

Good luck with your season.

 

[M67]

lightbulbHowever, I do believe that since humidity is water in the air, a bullet will drop faster at 1 mile to 2 miles in high humidity than in the Sahara desert with < 5% H.

As little as humidity means,
1. A bullet drops SLOWER in high humidity, as water vapor is less dense than air. To be exact, it doesn drop slower, but it loses velocity slower.
2. Humidity means far more in high temperatures than in low. This is because the vapor pressure of water is higher (100%RH is A LOT more water vapor at 30°C than 0°C)
3. 78%RH is the ICAO std. and a good average, it may be 98 in a rainfall, and 50 in a desert, but it hardly amounts to a click. I would say it is more relevant to account for the coriolis acceleration - and FAR more relevant to keep nazi-reloading routines to ensure low ES.
4. And some serious wind-reading skills.

I may be a completely retarded wind-reader, but i have shot some at 1000, a lot inside 1000(meter that is) and alittle out to say 1600m,
At the long ranges I miss a lot - but for about two reasons. Im talking first-shots here.
- wrong/inaccurate wind assesment
- bad form by shooter

In the beginning i missed to poor ammo, to not accounting for drift, coriolis, pressure, look angle, you name it - but with good data on the ammo and met/env, good dope from last, and lots of practice - i still miss - to Tony Boyers "friend" the wind...

K

 

[4xforfun]

T3-OleMan,

I am assuming these:

Altitude (ft) 9,928
Station Pressure (hg) 20.01
Temperature (F) 19 SNOW
Humidity (%) 99

Are conditions you are putting in for your Colorado hunt?

What unit are you hunting? I don't know how much humidity affects LR shots but 99% humidity here is rare - at 6 AM this morning, the most humid hour, we had 34% here in Grand Junction and it will be around 10-15% as the day warms. Daily temps are in the 70s and lows are around freezing.

You probably shouldn't come out here at this time of year, it'll make you want to stay

Good luck with your hunt!

Jack

I could be wrong, but if you are imputting ACTUAL STATION psi..(absolute?...IE..NOT CORRECTED) you do not need to imput alt. With my "Shooter" phone app, if I switch it to actual station PSI, the program will not even accept any alt imputs.

If I am wrong, please...someone correct me!!!

Tod

 

[jackem]

I could be wrong, but if you are imputting ACTUAL STATION psi..(absolute?...IE..NOT CORRECTED) you do not need to imput alt. With my "Shooter" phone app, if I switch it to actual station PSI, the program will not even accept any alt imputs.

If I am wrong, please...someone correct me!!!

Tod

Todd, I believe you are correct in using actual station pressure to be the most precise. Altitude pressure is an 'average of station pressures' at that altitude over a period of time.

Jack

 

[4xforfun]

Kinda thought I had it figured out...but when I saw the imputs he was using...PSI of 20.01!!!! That HAS to be actual station PSI, not corrected. With that imput, the 9928 ft alt imput is moot.

 

[T3-OleMan]

Kinda thought I had it figured out...but when I saw the imputs he was using...PSI of 20.01!!!! That HAS to be actual station PSI, not corrected. With that imput, the 9928 ft alt imput is moot.

Tod, you are absolutely correct. Don't get confused. When I go to the well I get the bucket full, the excess is free, if anything is ever free. When I go to a real world weather site I get ALL that is there for that elevation. I may need it some day in some other application, and it was ALL real that day!

I made a 1 page 11 row, 12 column EXL spread sheet for SC 500' and CO 8k', 9k', 9928' {Leadville(KLXV) i.e. Vail} and 11k' with Temps 0F, 10F, 20F......100F as the first Col.

All this is for Hornady 185gr GMX Superformance factory round and my zeiss-victory-diavari-4-16x50-t-fl-riflescope, on 338WM.

I use the Ballistics Calculator - Hornady Manufacturing, Inc (this is a new version )and the Zeiss Optical Long Range Reticle Analysis Prog to get the setting for Optimum Power to get max accuracy from my Rapid Z 800. Note that Adv. Hornady wants everything....even still wants humidity? I use REAL station pressure every time I can get it or calculate it cause (being an old pilot) I don't like averaged oatmeal!!!!!!!!!! Can be like the statistian who drown in a creek that averaged 1 & 1/4 IN. DEEP.
On my stock is taped reduced / colored-for camo- copy of this sheet.
Here is how it works:
When I get to hunting site.
Record outside temp.
Shut the engin off.
Set scope for Optimum Power Setting using the temp line @ Elevation.

This sheet also reflects the Temp effect on Superformance powder and how if it is 70F and I am 9,928' My GMX 185 goes out at 3,080 fps (on the box)and I must set my scope at 15.27X to get all cross hairs from 200 yds to 800 yds to be ZERO! For 900, 1,000+ yds I have hold over calcs based on the 800yd cross hair. However, if it is 0F my GMX drops to 2,997 fps (-83fps_powder sensitivity) and I have to set Optimum Power Setting to 14.00X. Now all I have to do is get my LEICA CRF 1600 to tell me the accurate Distance to target. I don't have large angle shooting places so I am the only thing that can fail. I can take the pressure. I've missed before and if I get enough opportunities I may fail again? Film at eleven.
Note : The CRF 1600 measured Chimney Rock at 1,968 yds as sun set behind it. Yikes!!

Had two ELK lined up but they would not both fit in the GRILL and under the hood so I stopped! Dadgummit, only ELK I saw in 9 days. Dang drought was bad last week. Think I'll go ML or 4th rifle next year.

 

[RMulhern]

Here's my 2 cents worth! New shooters coming into the LR venue often find it difficult to believe that SD is a goblin that will jump out of the bushes and eat their lunches but it doesn't take them long to figure out that "Hey....I've got a dead nuts zero on my rifle at 100 yards but my bullet impact was 14" right at 1000 yards!" Nothing can teach this better than when shooting long/slow/heavy bullets at long range. I've been shooting M1874 Sharps rifles for quite a few years now, in addition to all of my smokeless powder rifles, using cast lead bullets with weights ranging from 500 grs. up to 720 grs. with velocities running from 1250 fps up to 1400 fps. If I were to go up on my range here at home on an ideal day aka absolutely no wind and visible mirage and get a dead nuts wind zero from 100 yards and then go back to 1000 yards to shoot which I do on a regular basis and use the 100 yard wind zero....I probably wouldn't hit the 72"x72" mainframe steel plate with a good break and call!! Why? The same dead nuts wind zero that I had obtained at 100 yards would have the point of impact at least 35" to 40" right of my aiming point due to imparted SD delivered by the right hand 1-18" twist built into the rifles barrel! Spin drift is a natural law of physics and cannot be denied!