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Hornady .308 168gr TAP Ballistics

Posted By: Cody Malone

Hornady .308 168gr TAP Ballistics - 10/30/09 07:29 PM

iI need help with my new Remington R5 .308 w/ Leupold Mark 4 4.5-14x50mm LR/T M1. I am wanting to make this a long range gun (ie 500-1000yd) I am loooking at the ballistic chart and cvant quite figure out how to convert this to scope clicks? Im a young rookie so dont bash me to bad, lol. Here are the ballistics i have calculated

Ballistics Calculation

Input Variables Firearm type Long
Sight Height 1.5
Bullet Weight (grains) 168
Ballistic Coefficient 0.515
Muzzle Velocity (fps) 2700
Temperature 70
Barometric Pressure (hg) 29.53
Relative Humidity 78%
Zero Range (yards) 100
Wind Speed (mph) 0



Ballistics Table in Yards Hornady .308 168gr Tap
168 gr., 0.515 B.C. www.hornady.com

Range (yards) Muzzle 100 200 300 400 500 600 700 800 900 1000
Velocity (fps) 2700 2531 2368 2211 2060 1916 1777 1647 1524 1412 1310
Energy (ft.-lb.) 2719 2389 2092 1824 1583 1369 1178 1012 867 743 640
Trajectory (100 yd. zero) -1.5 0.0 -3.9 -14.0 -31.2 -56.7 -91.6 -137.6 -196.4 -270.3 -361.8
Come Up in MOA -1.5 0.0 1.9 4.5 7.5 10.8 14.6 18.8 23.4 28.7 34.5



Posted By: jeh7mmmag

Re: Hornady .308 168gr TAP Ballistics - 10/30/09 09:59 PM

To find the come up clicks you need to know the MOA of scope:
Look at your turrent and see what the MOA for scope is?
1/4MOA and 1/8MOA are common for hunt scopes.
Target scope maybe 1/16MOA and some are ELR are 1/32
Tell me what you have and we will fiqures click?



Posted By: Cody Malone

Re: Hornady .308 168gr TAP Ballistics - 10/30/09 10:39 PM

I believe 1/4 moa.

Posted By: jeh7mmmag

Re: Hornady .308 168gr TAP Ballistics - 10/30/09 11:20 PM

¼ sounds right
Your ballistic chart is showing a 100 yard POI of 0,0 (or right in the bulleye)
So For 1/4MOA scope:
1 click changes POI 0.25 “ at 100yrd
1 click also change POI
0.5 at 200 yards,
0.75 at 300yds,
1.0 at 400yrds
1.25 at 500yds
roughly



Lets take the 200yards figures and find the clicks required to bring POI back to Zero, Zero using a ¼ MOA scope.

Traject Chart show your POI is –3.9” at 200 yards
Which means at 100 yard it would be -1.9MOA (shown on Come up)
1.9MOA / 0.25 per click =7.6 clicks needed to change your 200 yard POI back to 0,0

It get confusing and you have to think in Minutes of Angle and not inches.
MOA is really a measurement of angle that just happens to be around 1inch at 100 yards, extended -2 inch at 200 yards. MOA=1.047197580733"

Most of this is worked up on spread sheet before hand and put on chart. Or figured with ballistic calulator or slide if field

Have your looked at your wind dopeing yet??


http://www.snipercountry.com/articles/mildot_moa.asp

Spread sheets are not hard to set up.

Posted By: jeh7mmmag

Re: Hornady .308 168gr TAP Ballistics - 10/30/09 11:29 PM

There are also some online calculator for LRS and ELRS that may also output the inch and MOA for you. Google JBM ballistic?

Also contact NTRP on the THF forum. I think he teachs LRS & dopeing.

Posted By: jeh7mmmag

Re: Hornady .308 168gr TAP Ballistics - 10/30/09 11:47 PM



Here is a simple spread sheet showing the clicks required for your parameters

come up in MOA / 0.25MOA scope= clicks

muz 100 200 300 400 500 600 700 800 900 1000

MOA--1.5 0 1.9 4.5 7.5 10.80 14.6 18.8 23.4 28.7 34.5

Clicks= 7.6 18 30 43.2 58.4 75.2 93.6 114.8 138


cheers

Posted By: Cody Malone

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 12:38 AM

Thanks for the lesson, do those sound about right, coeficent, muzzle velocity ect? I called leupold and ordered a custom turret?

Posted By: jeh7mmmag

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 01:26 AM

Quote:
Ballistic Coefficient 0.515

I can't come up with that high a number. I see several in that range that are .460 to .475.
That BC would effect the rest of there chart slightly. Can you verify the BC. I did not see that figure.


Muzzle Velocity (fps) 2700
24 inch barrel yes
If shorter than 24 subtract 20fps per inch


30 Cal. A-MAX 30502
Diameter Weight Ballistics Coefficient Sectional Density
.308" 168 gr. 0.475 0.253




Posted By: Brother in-law

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 01:44 AM

Im about to have to learn the same thing. I don't have time now, but I am going to go to NRTP's long range class soon.
I bought the Hornady 168 a-max's today to try.

Posted By: NTRP

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 01:53 AM

jeh7mmmag has you on the right path. MOA happens to be so close to 1 inch at 100 yards that most shooters think it is an equivelent measurment. But it isn't. MOA measures an arc of an angle.

To make it easy, look at your dope chart. If your range is 500 yards and it says your MOA adjustment is 7.5 MOA, just forget the clicks and inches. All you have to do is turn the knob to 7.5 MOA.

Now, with 1/4 MOA or 1/8 MOA adjustments there would not be an exact 7.5 adjustment. It would be either 7.4 or 7.6 give or take. That is where you have to learn how your bullet flies in different temperatures. More especially how it flies in varying density altitude. The only way you can figure that out is by shooting often in varying environmental conditions unless you have someone with you to teach you the affects.

Hope that helps.

Posted By: Cody Malone

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 02:03 AM

I'm shooting a stock rem r5, I have not measured the barrel. I obviously need to contact NTRB for some serious lessons.

Posted By: Cody Malone

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 02:08 AM

Originally Posted By: Brother in-law
Im about to have to learn the same thing. I don't have time now, but I am going to go to NRTP's long range class soon.
I bought the Hornady 168 a-max's today to try.


I have only shot my rig about 25shots, 100&200 yds. I can shoot 1 moa at 200 and a 100 I can shoot three shots in a dime, almost in the same hole!!! Those bullets in my rem r5 are the bomb!!

Posted By: NTRP

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 02:26 AM

5R's and rifles like BIL's are capable of great accuracy.

Posted By: Brother in-law

Re: Hornady .308 168gr TAP Ballistics - 10/31/09 03:52 AM

I came very very close to an r5. I did alot of research and the only reason why I didnt, because I wanted a 20" barrel. Your barrel is 24". I just got a bipod today, so I need to see what my groups will be

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