Ballistic calculator

[jimbires]

here is one I've used .

JBM - Calculations - Trajectory

www.jbmballistics.com

 

[FEENIX]

Scpoe height is 2.75

WOWZER!

 

[DDWing]

WOWZER!

That's from center of bore to center of objective. It's actually not that high for an AR15.

 

[FEENIX]

That's from center of bore to center of objective. It's actually not that high for an AR15.

Yes, but I did NOT want to assume it was an AR.

 

[xsn10s]

My AR is roughly 2.25". JBM worked well enough to hit sage rats out to 300 and chucks to past 400 last year.

 

[338 dude]

Its an Athlon Argos 6x24x50 MOA. It's definitely a 1/4 moa scope. I've tried these calculators with three different rifles, and they will not match up with any of them.

6.5 Grendel 20" proof research barrel
100gr. Lapua Scenar
Distance is 500 yrds
Altitude is 580
Pressure is 29.9
Temp is 79
Humidity is 52%
M.V. 2780
100 yrd zero
Athlon Argos 6x24x50 1/4"MOA
Scpoe height is 2.75
No wind, no angle
Shooting Nort/South

The two editions of Bryan Litz's book ballistic performance of rifle bullets did not list a 100 grain Lapua Scenar the closest one I could come up with is 108 grain

 

[asd9055]

The two editions of Bryan Litz's book ballistic performance of rifle bullets did not list a 100 grain Lapua Scenar the closest one I could come up with is 108 grainView attachment 302980

You can get the info from Lapua website

 

[338 dude]

The short and quick answer is garbage in garbage out one of your input must be off and off a great deal could be something as simple as a decimal point in the wrong place

 

[DDWing]

The short and quick answer is garbage in garbage out one of your input must be off and off a great deal could be something as simple as a decimal point in the wrong place

I have checked, and rechecked the information numerous times, and nothing lines up. This Grendel is a 1/4 moa rifle. I can shoot bullet drops, measure them, adjust my scope for said drops, and it's spot on. I just can't get the ballistic calculators to line up with the ballistics of the rifle. I have the same problem with my other rifles. I have a Remington 700 long range in 300WM, and I run into the same problem with it.

 

[asd9055]

I have checked, and rechecked the information numerous times, and nothing lines up. This Grendel is a 1/4 moa rifle. I can shoot bullet drops, measure them, adjust my scope for said drops, and it's spot on. I just can't get the ballistic calculators to line up with the ballistics of the rifle. I have the same problem with my other rifles. I have a Remington 700 long range in 300WM, and I run into the same problem with it.

Time to give BallisticAE a try, works for me

 

[DDWing]

Time to give BallisticAE a try, works for me

At this point I'll try anything. Right now, im just wasting components. I'm to the point that I'm thinking I'll just shoot bullet drops for each individual rifle, print my own ballistic dope cards, and forget about ballistic calculators entirely.

 

[venatic]

How are you getting your velocity? Chronograph I assume but which brand.

 

[DDWing]

How are you getting your velocity? Chronograph I assume but which brand.

I have a Caldwell ballistic precision. And a Magnetospeed sporter. I normally use the Magnetospeed.

How are you getting your velocity? Chronograph I assume but which brand.

 

[338 dude]

I have a Caldwell ballistic precision. And a Magnetospeed sporter. I normally use the Magnetospeed.

Sounds like the velocity is pretty solid the problem has to be elsewhere