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Advanced Marksmanship what am i doing wrong?...

.308nerd

Private
Full Member
Minuteman
Jul 30, 2010
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I went shooting out in the desert this weekend. I took my remington 700 vsf .308, and a box of reloads I had put together a few days prior. I also had several large cardboard pieces (3'x4' or so), and some silhouette targets to tape to them. I then proceeded to walk out to 100,200,300,400,500,and 600yds and placed the targets. I came back to where I had set up to shot, and got into the prone. I pulled out my Droid and entered all the info into the "Shooter" ballistic program. Temp, humidity, elevation, distance, degree of decline (fairly small maybe 3-4%). I had previously entered all the ammo info, and info from my rifle. I lasered the farthest target and got almost exactly 600yds. I put the info form Shooter onto my rifle, and aimed center mass. I fired my first shot (cold bore) and watched my round impact about 3ft in front of the target, and approx 1ft to the right of the target (I never have been very good at reading wind lol ). I was surprised to say the least. I thought for sure that using all of that data, the ballistics program could at least put my first round on paper...
Has anyone else had this problem? Am I doing something incorrect?
 
Re: what am i doing wrong?...

Fill out your profile & maybe some local shooter can help you..
 
Re: what am i doing wrong?...

I have my rifle zeroed at 100yds. I was shooting at the 600yd target.


I will try to get my profile updated tonight
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Re: what am i doing wrong?...

Hmm. Well, I guess if I was seeing what you were seeing, I would start out with the 100 yard target and move out from there. My guess would be that your MV does not equal the MV that you are putting in your ballistic calculator.
 
Re: what am i doing wrong?...

Sounds like you were trying to get everything right. However, in addition to possibly having too low of an actual MV, you may not have a really accurate BC for your bullet (at those ranges either G1 or G7 will do but if the BC is inflated, it will lead to overly optimistic results).

Also (and I'm not saying you entered them incorrectly because it sounds like you did), make sure that your ballistics calculator has the correct inputs for altitude and barometric pressure and that it knows whether you are using station pressure or standard (corrected) pressure. I haven't used Shooter, but the comparable Ballistic for iPhones/Touches requires you to set "Pressure is Absolute" to ON when using 0 (no) altitude and station pressure, e.g. 26.8 hg, vs. entering the altitude, e.g. 3000 feet and 29.92 hg, which would require turning that setting off.
 
Re: what am i doing wrong?...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Pat M</div><div class="ubbcode-body">computers & input VS real world
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</div></div>

Yup.

I'll play Carnac the Magnifacent for you-put the fourth dot down on your mildot reticle on the center of the target and hold half a mil into the wind if its a light breeze.
I'll bet I get you closer than your phone did.
 
Re: what am i doing wrong?...

I was using Ballistic FTE and it was off by 2.5 to 3 MOA off from the actual dope.
I used the Sierra 175gr SMK variable BC originally. I later changed it to an actual G7 BC of .243, dited my MV just a bit and turned off the absolute pressure.
This gave me much more accurate results. Results at that point were only .5 to 1 MOA off.

It's all about the info you have entered. Play with that and see what you get.

R.
 
Re: what am i doing wrong?...

Also make sure u didn't put a mil input when it should be moa or the other way around. I use shooters on my Droid to and love it bit at first that's the mistake I made and hit dirt infront of my target at 520yd.
 
Re: what am i doing wrong?...

Three feet at 600 is not a BC or MV issue.

Aim higher.
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Re: what am i doing wrong?...

Ballistics FTE is off, and this is after chronoed rounds and put in the calculator. It can only get you close but not dead on.
 
Re: what am i doing wrong?...

I've always had to fiddle with computer dopes to make the curves (real world/computer) match.

Best way to do it is start short and work your way out. Record on paper then input into computer and see if the curve matches. On a new bullet, I'll always record the conditions and then shoot from 100-1000yrds and manually record the impacts on paper then I graph out the curve on graph paper. Once you have all that curve matching on the computer is easy.
 
Re: what am i doing wrong?...

Ok, I gotta chime in. Call me old fashioned, but I fall into camp with Shot in the Dark! Just shoot, record, shoot some more, build a history. If you spend more time on the trigger, the computer will be asking you for the info. LOL!
 
Re: what am i doing wrong?...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Robot Doc</div><div class="ubbcode-body">Ok, I gotta chime in. Call me old fashioned, but I fall into camp with Shot in the Dark! Just shoot, record, shoot some more, build a history. If you spend more time on the trigger, the computer will be asking you for the info. LOL! </div></div>

LoL you are right! The software I got was dead on up to 300y after that it just goes south. HARD DOPE is the way to go. Everytime temperature drops/rise 15• I have to chronograph rounds and record HARD DOPE.
 
Re: what am i doing wrong?...

Shooter has been very accurate for me but I do the following:
1 chrono, sight in and record all your atmosphere from your load at 100yds
2 shoot with that data entered in the program at distance....I use 400 yds
3 read the target group in the vertical and take note of mils off at that range
4 go back into shooter and adjust your muzzle velocity to reflect how you shot at 400.

My MV is always.....(and it's because I use a just good enough for a reading chrono).......off some. The program allows you to adjust MV while watching the data change in your solution table.

This will give the program some good real world input and once verified and tweaked with real world dope it is very accurate much farther out.

For windage use it only as a basic guide......this is going to take lots of shooting in lots of conditions to get good

Think of all ballistic programs like a long range bore sighter.......they will get you on target and sometimes be very accurate but many times will need some tweaking.
 
Re: what am i doing wrong?...

OP,

You could have a multitude of errors. Here are two that have not yet been alluded to: parallax and an inconsistent position. Each of these concepts produce angular error which increases with distance. At short range, like a hundred yards, the effect of these errors are masked, making the novice perceive that marksmanship is about equipment rather than knowledge and skill.

If the ballistics math is correct for standard atmospheric conditions then look into learning something about wind and weather effects, remember the bullet is effected by gravity, drag, temperature, and wind. Also, be sure to calculate for slope.

Elevation error can also be the result of thoughtless stock-weld and/or butt-to-shoulder placement, as well as an inconsistent eyeball/eyepiece relationship. Failure to follow-through is another cause for a shot to hit low. Be sure to call your shots, plotting both the call as well as the actual strike. The corollary can help you troubleshoot for the source of error, which, unless the equipment or platform is broken, will always be from your failure to account for everything that's important to hitting where aimed.

 
Re: what am i doing wrong?...

I've only used the shooter program out to 400 yards, but it got me real close.
 
Re: what am i doing wrong?...

Maybe try walking before you run. Get on and good at 100, 200, 300 and so on. Build your way up.
 
Re: what am i doing wrong?...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ubet</div><div class="ubbcode-body">Maybe try walking before you run. Get on and good at 100, 200, 300 and so on. Build your way up. </div></div>

He's right. Start at 100 and work your way out. That way if your ballistics program is continually off by a few tenths of a mil or a few quarter MOA you will see it sooner, and when it matters less to your POI.
 
Re: what am i doing wrong?...

I would throw a litany of questions at you... You have a 100 yard zero for a .308? That would put your POI at approximately 105" for a 168gr (I just guessed that is what you are using). Is your scope up to that adjustment? If you zeroed to 300 yards then all you would have to dope for is 72" POI which would be easier to manage. With a 300 yard zero, between point blank and 400 yards your POI spread is +6.5" and -14.0 which can make life very easy. Can you shoot a box at 100 yards? If you do, do you pick a random MOA and verify the results? Do you practice any shooting positions, sight picture, breathing and trigger pull without firing? Repetition and muscle memory go a long way in the long range game.

There's too many variables in this equation... What kind of scope are you using? Is it level? Was the rifle canted when you took the shot? What is the scope height? Are you using a 20 MOA base? What support are you using? A bipod/sling? What are your typical results at 600 yards? Why not shoot some GMM and verify your rig's capability before trying to work a hand load? Why not work <span style="font-weight: bold">out</span> to 600 when trying the new home brew?

Just a few questions and thoughts.
 
Re: what am i doing wrong?...

Alright I will admit that I didnt read all of the above but I found your problem. I decided to pay for the program on my phone to figure this out. I didnt think it could have been your rifle.

Go back to the entered load data......

Look at the Velocity you entered for your round....

Just to the right of it is a box that auto fills for velocity change because of Temperature and it is set WAY TO DAMN HIGH!

Set it to zero for now, re-run it and see if it comes up correct. I ran this against my ballistics program and its dead nuts on. In fact since Ive started to play with this thing I think Im going to keep it, its kinda bad ass......

Tell you what, give me:

-Velocity
-Bullet BC
-Bullet Weight
-twist
-altitude
-Temp
-Scope Height (as accurate as possible)
-Zero distance
-Target incrament

Get me these and Ill send you a Ballistic graph to compare with.
 
Re: what am i doing wrong?...

Forgot to add, the auto set temperature adjustment for the velocity droped my velocity 500FPS for a 40* temp difference if I remember correctly......Once I changed the offset to zero it was right on with my other program.
 
Re: what am i doing wrong?...

Next time , take some lawn flags...since you're not good at reading temp using the mirage method....
 
Re: what am i doing wrong?...

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: longrange****</div><div class="ubbcode-body">Forgot to add, the auto set temperature adjustment for the velocity droped my velocity 500FPS for a 40* temp difference if I remember correctly......Once I changed the offset to zero it was right on with my other program.</div></div>

What did I miss? Wouldn't a 40 degree change in temp be worth something like 100fps/2 MOA, or about 12 inches at 600.
 
Re: what am i doing wrong?...

What optics, may not be adjusting correctly? Where did you get your velocity number? Chrono,factory,

Each rifle and barrel is different that is why Data books are still useful,

Just a couple of quick thoughts