Please help - pocket DOPE card

[taewa]

Can anyone please help me with a couple load calculations? I am trying to prepare a sticker to put on my scope for hunting season to estimate yardage at each of the hash marks. I don't have a chronograph. I have the Viper HD 5-25 x 50 SFP scope VMR3-MOA reticle. My sight height is about 42mm (1.65in). I have a Seekins PH3 in 7PRC. I plan to hunt in Idaho around 3000-4500 ft. Zero at 100 yds. I am between two loads, so if you could send for each, that would be great. I did a ballistics calculator, but I don't know how to take that info and translate that over to my specific reticle.

1. Barnes 160gr LRX BT = 3050 fps
2. Federal Premium ELD-X 175gr = 3000 fps

Here's what I got from the Hornady site:
Bullet:HORNADY 7 MM 175 GR ELD-X
Muzzle Velocity (ft/s)3000
Wind Angle (°)90
Barrel Twist (in/rev)8
Altitude (ft)0
Bore Diameter (in)0.277
Pressure (inHg)29.92
Sight Height (in)1.65
Temperature (°F)59
Axial Form Factor1
Humidity (%)50
Zero Range (yd)100
Shooting Angle (°)0
Zero Angle (°)0.05333
Max Range (yd)500
Wind Speed (mph)10
Interval (yd)100
TRAJECTORYRESULTS

[th]

Range
(YDS)​

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[th]

Total Come Up
(IN)​

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[th]

Total Wind Drift
(IN)​

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[th]

No Wind Trajectory
(IN)​

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[th]

Wind Drift
(IN)​

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Gyro​

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[td]0[/td][td]1.7[/td][td]0.0[/td][td]-1.7[/td][td]0.0[/td][td]1.77[/td] [td]100[/td][td]0.0[/td][td]0.4[/td][td]0.0[/td][td]-0.4[/td][td]1.89[/td] [td]200[/td][td]2.6[/td][td]1.6[/td][td]-2.6[/td][td]-1.8[/td][td]2.03[/td] [td]300[/td][td]9.9[/td][td]3.7[/td][td]-9.9[/td][td]-4.1[/td][td]2.19[/td] [td]400[/td][td]22.4[/td][td]6.8[/td][td]-22.4[/td][td]-7.4[/td][td]2.34[/td] [td]500[/td][td]40.7[/td][td]11.0[/td][td]-40.7[/td][td]-12.0[/td][td]2.50[/td]

Do you need any other info from me? Thanks so much!

 

[Antares]

 

[Koda_]

You need to know your velocity and confirm with practice at the distance you want to hunt. At this point youd be better off with a 200yd zero and keep your shots under 300yds max and youd be fine.

 

[pender1]

ShootersCalculator.com | Ballistic Trajectory Calculator

Calculates the ballistic trajectory of a bullet fired from a rifle, handgun or other firearm. Produces a ballistic trajectory chart and table that shows the drop, velocity, kinetic energy, windage, and trajectory of a bullet.

shooterscalculator.com

Just make your own. I have one printed out and laminated for most of my rifles.

 

[alexnelon]

Knowing your velocity is pretty mandatory for ballistics calculators.

The only way to get reliable DOPE without a chrono is by shooting and recording the drop at different ranges.

You can ballpark it and get close, but you're not going to be close enough without truing your ballistics out to ~1,000 yards.

 

[jfk69]

How do you know the velocity of either of those loads without a chrono?

 

[MuleyFever]

As others have said, you need to know the velocity from your rifle, not what the box says. You can go shoot at 100 (zero) then 200, 300, 400 and measure your drops. Then use the ballistic calculator to tune the velocity until it matches your actual drops. Personally I have not had a lot of luck doing this, it just never seems to match up quite right. I think its because you need at least probably 10 shots at each distance to get a good idea of the center of your cone. I didnt shoot that much when I tried it.

 

[taewa]

OK guys... I was able to talk my friend into coming with me to range with a chrono. Here are the numbers:
Fed Premium 175 gr. ELD-X= 2923, 2938,2926, 2921
Barnes 160gr. LRX BT = 3074, 3055, 3064

I assume I average each group and that's my true velocity, but still unclear on how to translate all that into my MOA reticle sticker, so that each has mark has a "distance" lined up with it. Thanks for guiding the newbie along.

 

[wapitibob]

You need to get a zero, then shoot at 500-600 to verify the drop, regardless of what the chrono says.
You then adj the velocity so the ballistics app lines up with your actual results. At that point the app will tell you the moa/mil at each distance you want. Or, stick an Avery label on the turret and mark the yardage at the appropriate hash marks. That data still comes from the ballistics app.
And after that you have environmental conditions to consider...