Home Forums Hunting & Shooting Long Range Hunting Listing every calculation & consideration for precise 1st rnd hit.

1)Distance/MOA come up adjustment
a)corrected for temp deviation
b)taking into account usual cold bore deviation
c) corrected for angle shots up/down
d) corrected for elevation/altitude deviation
e) corrected for barometric pressure deviation
f) discounting humidity as negligible
g) discounting coreolis except past 750 to 1000 and beyond

2)Wind/Mildot hold off or moa crank
a) corrected for movers
b) converted from moa to mils for hold offs
c) taking into account normal cold bore deviation

3) Crank the paralax to infinity to flush out the slop, and dial it in

4) Establish natural point of aim

5) One deep breath to get oxygen in the blood. Breath normal and break trigger at natural pause. Focus on reticle

6) Don't wait for perfect sight picture, just send it.


7) Follow through, hold trigger to rear and call shot, ride recoil.

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Am I forgetting anything?

If you have a data card already established for the proper altitude and expected weather conditions you can cancel out 1a, 1b is more likely cold shooter, d is covered already with data card, e, f and g are all ignored.

2a is taken care of by the fact your long range you can wait an animal out, b is eliminated by using mil reticle with mil adjustments, c again is more of a product of cold shooter.

3,4 and 5 are on the money.

6, sorry if Im pushing the mechanical abilities of the rifle Im going my best to make it as perfect as possible.

7, part of my follow through is getting ready to make any corrections and send a second shot if necessary.

Thanks for the feedback bro!

I am still wrapped around the axle so to speak when it comes to the thickness of the air. Elevation and barometric go together so says the Lilja website. Density elevation or something like that. I understood it once but it fell out of my head.

Here is another link for making data cards based on density altitude.

http://www.arcanamavens.com/LBSFiles/Shooting/Downloads/DA/

There is no formula for a precise first-round hit at long range. Too many variables that cannot be controlled.

The things listed above are going to get you close, and often times a hit, but there's no guarantee.

It's important to be watching to spot that first shot, and make a quick correction/holdoff and send a fast second shot. The second shot should not be underestimated.

Trigger control is also very critical, and dry-fire is a good way to evaluate/improve it.

A first-round hit is what seperates the men from the boys. Give me a couple sighters, and I can PELT stuff at longer ranges. But if I have to hit on the first shot, much MUCH harder. Guess that makes me one of the boys <g>.

The other day I was shooting into a headwind. It resulted in an updraft- about 2 feet at 600 yards. I never would have called it that way. Anyone who could have laid on that landing and called that updraft and corrected and gotten a first-shot hit would have been manly indeed.

24 inches at 600 yards UP, in an updraft... care to describe the contours and wind speeds in the draft? I"ve seen a lot, but I've never seen that bad on elevation issues.

Jeff

It was that normal place I shoot Jeff. The wind felt pretty much straight on. But everything I brung, was hitting high. The 2 feet is an estimate, but that's about what it looked like.

I'd estimate the wind was in the high teens or low 20's, but hell if I know. It was windier than I'll usually bother with but I was in need of some recoil therapy <g>.

It's important to be watching to spot that first shot, and make a quick correction/holdoff and send a fast second shot. The second shot should not be underestimated.

Trigger control is also very critical, and dry-fire is a good way to evaluate/improve it. [/quote]

This is part of the mental drill I intend to practice when I can't get to a range. My math skills are so crappy and I find I have to force myself to focus HARD to get mils/moa back on the top of my brain. I was thinking of making practice flash cards or something; for instance, 2 feet at 482 yds is ??moa and ?? mils. My ground hog bud is a whiz at this, but I really have to get in the zone. It don't come second nature yet. I am working on some cheat sheet tables.

John Antanies used to write for Varmint Hunter. He said that if he has a rifle available he dry fires EVERY night, exceptions being I assume when he is on the road for business.

Thanks! Very useful stuff. A link like that is one reason I cannot break my addiction to 24hrcmpfr! Thanks again.

Thats a damn sure wow from me with the calibers you run in a 20 mph cross wind, the cross factor of it wouldn't approach 24 inches I wouldn't think, much less the updraft factor. I always thought, on ranges at least, that an updraft factor was MOA or less of an issue generally.

NOW if 20mph was blowing straight up out of canyon and caught the bullet out of the blue so to speak... it would be the same as a full value correction and could approach 4 moa in even a gun like you shoot I'd bet. I don't have my wind rosettes handy though.

Rost, dosent a head or tail wind simple act as an addition or subtraction of the base velocity (wind mph x 1.67=FPS)?

I was a little thrown by the 2 feet reference as well.

Dixie,
By all means cheat and make up cards that you can attach to your rifle. I even have a cheat sheet in my car for when Im bored (stuck in the car for way to long sometimes). In addition to the data cards I have a mil based reticle printed on the back of the card with yardage marked at the appropriate marks. If you move the magnification to a predetermied point (usually max power) you can use them for quick holdover marks. Much easier with a first focal plane scope but it can be made to work with most scopes. I will try to post a picture of it tonight when I get home.

Interesting read on the 2 ft. rise.
Some years back I was shooting 600 in a HP match. We were at a small range, 6 points, and the shots crossed a large area of marsh grass. Sun was out, it was warm. Very little wind, I could see the boil from off the grass. Both sighters were in the 10 ring. As I lay there waiting for the targets to come up, the sun went behind a cloud bank, where it stayed for the rest of the string. I figured my first record shot would be high, and it was, in the seven ring! A 12 0`clock 7....couldn`t believe it. My scorer couldn`t believe it. Now, do I make a correction from that first shot, or was it a fluke? I`d called a center hit. I made the correction, and ran the target, with 13 x`s.
In couclusion, I think the two feet possable.

CG
But what you saw rise wise was mirage differences. I was thinking that Jeff would have had enough sense to mention that as a possible cause. Mirage can do that to you big time and its why folks don't make correct corrections sometimes... add an increase or decrease in conditions, IE wind, and couple that with a light change that produces or eliminates mirage, you have to correct for both the condition change and the apparent vision change. Both are seperate issues and could .... theoretically.... cancel each other out.

When I was still just ranked as MA in shooting HP, I had same issues with light and elevation, but the more I shot the better I became to the point I found a hold that would eliminate the elevation differences, or if you can't, you learn to correct for them.

Varmints
yes a simple correction basically, IE my recollection, not having shot since 2003 past about 300 yards and nothing in competition, that generally head and tail winds were MOA or less issues, generally speaking.

Jeff

I still write for The VARMINT HUNTER Magazine. And I still dry fire every day. Did so today, but not yesterday because I was out shooting. I shot sitting at 640, 700, and 715 yards from my bipod sit position and will admit I was completely fooled by the wind for the first round shot. As one poster points out, it is easy to adjust from that first round. Elevation was perfect; I had clicked down 2 for angle and temperature.

I have never seen a huge amount of vertical dispersion; maybe an MOA or so max in a boiling mirage. Problem for me now is that I live in AZ and there is almost no mirage. Very often the wind will blow one way at 700 yards and a completely different way at 200, and there is no way to tell (we are talking small breezes here, but it doesn't matter - wind drift at 700 yards is a killer).

When I shot competively with iron sights, the light angle had a lot to do with bullet impact. Any observations from the crowd here about light, particularly light coming right over the horizon to your right or left when shooting with scopes?

In terms of headwinds/tailwinds, by far the most frustrating thing is a fishtailing wind - do the trig on a wind going from 5 oclock to 7 oclock and it will kill you at 700 yard; the drift is about 1/4 full value, but right to left one minute and left to right the next.

John Antanies

Mr Antanies...

It is with great pleasure I welcome you back to 24hour since your last post in 03

Stick around!

Your practical articles on things that really matter have helped me MORE than any other I have stumbled upon.

I have some questions on range finders when you have the time.

Montana Marine,
Speaking of variables, I used to read precision shooting magazine and they were fanatics about getting the barrel super clean.
Not long ago I was at a rifle match where they allowed no sighters
and one high master stormed off the range and refused to compete unless he could fire 7 sighters.

How does someone with a clean rifle make a long range hit without the benefit of fouling shots?

Dixie:

Thanks for the kind words. I think sometimes I fear I repeat myself, but one thing I know is that if you are going to write about long range shooting, you best be doing a lot of it. If you still get Varmint Hunter you will find my email there; shoot me yours and your phone number if you want to chat about laser rangefinders.

The LR in my name stand for two things: long range and laser rangefinders.

I haven't posted in a while becasue I got tired of one two guys who acted like "bullies." So I left. I only came back for this because I saw your note when I was searching my name on Google to find a link to a Rifle Shooter story on line.

Whelenut: just my opinion, but I think a really accurate rifle will put its first shot right on the money with a clean bore. The secret I think is to make sure the bore is abosolultely devoid of cleaning solvent or oil. I run through about 20 dry patches and my first shot is on the money. Today I took out two rifles: a 7 STW and a .300 SAUM. My first shot (clean bore) with the SAUM was at a rock 550 yards away. Shot sitting with a sling. Held a bit for the wind. Bullet was about one inch low and 4 inches to the right. That is pretty typical. I then shot at 640 and 715 yards with no surprises.

Here is another observation of mine: if you only shoot long range at the same physical place every time (shooting range, etc.) you are fooling yourself. You will almost subconsciously learn the little nuances of the wind, etc. at that range. The next thing you know, you are hunting somewhere where you haven't practised and you get fooled big time.

LRNut,

Light angle does make a difference on POI. I log cold bore shots regularly, and write down all pertinent data, to include angle of light. Im shooting a rifle capable of shooting 1/2 MOA at 1000 yards on a good no wind day, and always within a minute, so its accurate. Light angle from 90 degrees left or right will "push" my CBS up to 3/4 minute. Ive read it has no effect with scopes, but my data says different, for ME anyway.

On CCBS-Clean Cold Bore Shot, It depends on the rifle, and the distance. In the 3 custom rifles Ive owned, they would shoot to the same POI at 100 yards, even with the CCBS, at distance however, they would be off around one minute. Chronograph confiremed this in all 3 rifles, as the first shot would be anywhere from 60-80 fps slower. One took up to 4 shots to get to the "normal" velocity. Now, in a factory PSS 300WM, I notice no difference in CCBS, even at distance? I can only think its cause the barrel is so damn rough that I cannot get all the copper out no matter what Ive tried. I gave up a long time ago, cause it doesnt matter, its a hammer. Take it for what its worth, but those have been my experiences with my rifles.

Your dead on about shooting at as many ranges as you can. Just shooting at your home range is not enough to really get good. They ALL have their own personality and nuances. An old SF Major told me that a long time ago when I first got into LR shooting, and he was of course correct.

JimD.

Here's a pic I've probably posted before. I'm a few hundred feet higher than the target. Wind sometimes pushes up the slope and I get wild high shots over the target. Consider that a 10 MPH full-value x-wind will push my bullet about 65" at this distance. So even a 3 mph updraft could raise poi 18" or so and cause a miss high.

So, in my opinion/experience, depending on terrain and wind conditions, updraft wind can be quite real and can have a significant effect on the bullet's path.