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EddyBo, if you change the BC and then have to run a stepped BC you are barking up the wrong tree! Tight primer pockets along with a crono reading are at least 2 indicators that your velocity is on. You have already confirmed the BC in another rifle shooting at slower velocities.

With all the Data you have you have at least mathematically proved what it is not.

From a mathematical standpoint this is what I believe to be the missing equation. It is BULLET ARC! An easy mathematical test will confirm. Even though your rifle printed one in high at 100 yds this will not take into account the changed duration of Bullet Arc that occurs especially in a high BC bullet pushed at 3200. Not to mention the bullet Arc can respond differently in differing barrels.

Try changing the point of impact figure at 100 yds to 2" high and so on and see if your charts don't line up near perfect. If they do then you will have proven from a mathematical standpoint the missing equation. Less than 2 minutes on your computer will confirm.



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What is your level of training in mathematics and physics? I'm having trouble following you.

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Originally Posted by rcamuglia
I wouldn't even worry about it.

Just shoot and confirm drops as far out as you can and record them with pencil and paper. Go into your ballistic program and play with the velocity number till the program outputs the same drop values you recorded in actuality.

I think when you have done that, the velocity figure you have determined works with all the important parameters in sophisticated ballistic software is more accurate than most readings you'll get over a chrono


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Originally Posted by mathman
What is your level of training in mathematics and physics? I'm having trouble following you.


I took the minimum required to get my degree so I could get on with law school. But I took a half semester of crash cal. Had to drop it before ruining my gpa smile

Here take e=mc2 say a certain amount of energy is released from the reaction say the theory does not work out for some explained reason. Do you just fudge the mass? All of it over my head anyway. The only thing bcs are to me is the number I have to use to get a desired result. Instead of changing the constant In the theory I want to know why m does not equal mass. Does that make sense? Hard to relae what I am saying on a phone and sober smile

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Conversational description:

Often times the coefficients c in a math model for some unknown quantity q are not really constants, but are themselves variables which depend on q. This presents a kind of logical feedback loop which is not always easy or even possible to decouple. If the variable coefficients c(q) are nearly constant for a range of different values of q, then it may be reasonable to substitute constants c in the model and still keep acceptable accuracy. But change q enough and the approximating constant c being used instead of the variable quantity c(q) may need to be revised.

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Uhhhh okay. I will just shoot when I get there. If it works it works.

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EddyBo, the flight pattern of a bullet apon exiting the muzzle is not a constant. For instance. A rifle with a 200 yd zero will produce 2 intersections of the scope line of sight and the bullet flight. If the scope is 1 1/2 " above the barrel the bullet exits the muzzle 1 1/2" below the line of sight. Somewhere around 50 yds the lines will cross basically achieving zero. At 100 yds you might be 1" high. Again at 200 the lines intersect again achieving zero.

You can run the same bullet and load threw the different rifles both with a 200 yd zero. Will the first intersection appear at the same distance. The answer is not nessasarily. The reason behind this is Bullet Flight Patterns. When a bullet exits the muzzle it responds somewhat like a curve ball and can be effected less or sometimes more depending on whether the bullet exits at the top of or bottom of a pressure node.

A little about bullet flight pattern......When a bullet exits a muzzle it first curved downward then curves upward. How drastically the bullet curves upward can sometimes under the right circumstance be effected to a much greater degree though it doesn't happen that often. Because bullet intersection varies at the first point of impact means you can not rely on the scope height measurement. The scope height measurement is simply a trajectory figure. When bullet flight patterns are in effect throwing a sharper......in this case....upward curve ball....the trajectory is greater than the scope height figure you are useing. The scope height figure cannot be relied apon. Physics however and BC's can.


Change your scope height figure and when you put in the number that identifies the true trajectory your chart will fall into perfect alignment to way out there.

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Just like I thought...


Originally Posted by Bristoe
The people wringing their hands over Trump's rhetoric don't know what time it is in America.
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so I should now fudge this instead of velocity? That is not what Brian litz said a couple years ago when we argued this to death on another forum.

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Fudge what? My post above was in response to a bunch of gobblety gook I didn't get.

If you're referring to scope height, just make sure you input an accurate number. Measure the scope tube diameter, divide by 2, measure bolt diameter and divide by 2 add both to the measurement between the scope on the gun and the bolt in the raceway

Make sure all of your inputs to your program are accurate in the atmosphere department.

Jordan and I were comparing output on 3 rifles and couldn't achieve the same output. When we got on the same page atmospherically with some of the other variables turned off, we jived.

Then you could also calculate the precise BC of the bullet fired from your rifle, which can vary between rifles with the same projectile. Chronograph close, chronograph far, then calculate. (Multiple shots at each range)

I've never gone to that extent but have a friend who does. I find that if all inputs are precise, simply adjusting the velocity figure will allow my program to output drop data that will match my actual shooting.



Originally Posted by Bristoe
The people wringing their hands over Trump's rhetoric don't know what time it is in America.
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Originally Posted by Fotis
Originally Posted by rcamuglia
I wouldn't even worry about it.

Just shoot and confirm drops as far out as you can and record them with pencil and paper. Go into your ballistic program and play with the velocity number till the program outputs the same drop values you recorded in actuality.

I think when you have done that, the velocity figure you have determined works with all the important parameters in sophisticated ballistic software is more accurate than most readings you'll get over a chrono


YUP!



Same here. I just use software to give me approximate come-ups. Then after dialing at all the distances out to 1,000...I record the actual numbers and print them on my cheat sheets. Just too many variables to be an exact science...for me, anyway. grin


Originally Posted by archie_james_c
I should have just
bought a [bleep] T3...


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Eddybo....

1. You know your velocity figures are accurate.
2. You know your bullets are not magic and somehow have a BC rating that exceeds everyone else.
3. You know the changes in weather you are entering are accurate.
4. You've tried to adjust all of the above and none of it has fixed the problem.
5. The reason is because the issue is an angle of trajectory issue that is caused by bullet flight pattern.

I only need three numbers and I can accurately do the adjusted and accurate trajectory computation for you in two minutes or less and the proof in the pudding is I will produce for you an extremely accurate and reliable chart.

What do you have to lose?

All I need is

1.Scope height
2. Velocity
3.Advertized BC ( not Brian blitz)
4. How many minutes you dial at a given yardage in the field. ( not what it says on paper.

The proof will be that my chart will jive with everything you have come up with shooting in the field and it is accurate and reliable.

No Stepped Charts!!!

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EddyBo Offline OP
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Shod I have done this chit hundreds of times. I have had this issue twice both times with this rifle. I ran down to the southern most part of the ranch we are hunting today and shoot out to 1640. Bastid put a cold bore shot dead center of a rock about a foot across with 4moa of windage dialed. It just pisses me off when chit ain't right and this chit ain't right even if it fuggin works perfect.

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[Linked Image][Linked Image]

The gratuitous rifle cell phone shot.

I would shoot this one past 1k at a deer but am limiting the wife to about 700 on an elk.

[Linked Image]

The nephew is good to about 800 with my wizzum


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Ooops svrewed that up my fingers might be drunk. Big hum is my 338 the other is the 280a! My wife is using. This is the wizzum the nephew is using.

[Linked Image] we got within a mile of some elk today but they got off the property before we could close the gap for them.

[Linked Image]

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EddyBo,

That is a fun photo. What magnification setting did you use?


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Sierra lists different BC's depending on velocity. Is it possible Berger has not tested that bullet at 3300 and indeed your true BC is actually higher than advertised? Then as it decelerates the BC decreases. In order to accurately map this then a stepped BC may be needed.


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Originally Posted by Ringman
EddyBo,

That is a fun photo. What magnification setting did you use?


60 through my antique kowa with a cell phone.

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