Thread: Downhill shot

I have never been in the situation where I had to shoot at long hunting range 300m+ downhill. I'm planning a trip where I will probably be in such situation.
I have been playing with the Hornady 4dof app and Ballistic advanced edition:
Both give the exact same elevation at 300m and 0deg (1.65 mrads).
However the Hornady 4dof app give only 0.98 mrads of elevation at 30deg while Ballistic AE gives 1.28 mrads.

Using the Rifle's man rule (cosine30deg x 300=260m) to get the true ballistic range (TBR) I get 1.26mrads. Ballistic AE result is pretty close.

Did anyone managed to practice at angle and compare shot with the Hornady 4dof? I have been using Hornady 4dof at the range, it is pretty much always bang on. I have no way to practice at angle, it would be great to know if the app is accurate enough at angles or can't be trusted.

Wanna post up your ballistics? Bullet, BC, velocity, atmospherics, etc? I'll put it into strelok and see how it compares.

Originally Posted by Pommy

Wanna post up your ballistics? Bullet, BC, velocity, atmospherics, etc? I'll put it into strelok and see how it compares.

Sure, I used the same date in Ballistic AE and Hornady 4dof:

BC 0.646 (Hornady 6.5mm 140gr ELDM
2500fps
100m zero
sight height 2"
Barrel twist 1:8

atitude 0
temp 20degc
humidity 60
pressure 1013.31
wind speed 0

Originally Posted by tibo

Sure, I used the same date in Ballistic AE and Hornady 4dof:

BC 0.646 (Hornady 6.5mm 140gr ELDM
2500fps
100m zero
sight height 2"
Barrel twist 1:8

atitude 0
temp 20degc
humidity 60
pressure 1013.31
wind speed 0

@tibo , I dont know what the intended quarry is but with a low powered cartridge as above the effective range wont be too far on a Red Stag.
We need 1500 foot pounds energy and an impact velocity over 2200 fps as a safe minimum for an adult stag.
It was Col Townsend Whelan that came up with the 1000 fp, minimum but that was for Whitetail with heavy slow big cals around 1930

Originally Posted by Moa Hunter

@tibo , I dont know what the intended quarry is but with a low powered cartridge as above the effective range wont be too far on a Red Stag.
We need 1500 foot pounds energy and an impact velocity over 2200 fps as a safe minimum for an adult stag.
It was Col Townsend Whelan that came up with the 1000 fp, minimum but that was for Whitetail with heavy slow big cals around 1930

1500lbs? I have been reading 1200lbs and 1900fps a few time. I was planning to get a 300wsm at some stage it would be more suitable then

Originally Posted by Moa Hunter

@tibo , I dont know what the intended quarry is but with a low powered cartridge as above the effective range wont be too far on a Red Stag.
We need 1500 foot pounds energy and an impact velocity over 2200 fps as a safe minimum for an adult stag.
It was Col Townsend Whelan that came up with the 1000 fp, minimum but that was for Whitetail with heavy slow big cals around 1930

Originally Posted by tibo

1500lbs? I have been reading 1200lbs and 1900fps a few time. I was planning to get a 300wsm at some stage it would be more suitable then

I'm really not going to go into this any more than there is no hard and fast rule, a lot of it depends on bullet type and construction as well as velocity and shot placment, foot pounds etc etc.
Moa you certainly wont go wrong with those figures but they are not set in stone depending on other parameters.
I will not be drawn further on this other than to say "do your own research before experimenting on animals" (that last comment is not directed at anyone just my personal opinion)

I do not advocate taking shots at ranges where bullet performance is Marginal, more than enough is always going to be better than just enough

Should be drop for 260 but windage for 300

I get 1.3 MRAD. That's rounded to 1dp.

cheers, that's really close to Ballistic AE. Not sure what's happening with Hornady 4dof

Hi Tibo
Just put your data through my ballistic app and at 260m on the flat it calculates -1.1 mil. I think they are all guesstimates, my app is Exterior Ballistics. If you sighted in at 200 the drop at 300 would only be 9.1", and the 300m (260m) shot downhill only -4.6" low, meaning your aimpoint adjustment would be minimal.
Cheers
Ruger7mm

Originally Posted by Ruger7mm

Hi Tibo
Just put your data through my ballistic app and at 260m on the flat it calculates -1.1 mil. I think they are all guesstimates, my app is Exterior Ballistics. If you sighted in at 200 the drop at 300 would only be 9.1", and the 300m (260m) shot downhill only -4.6" low, meaning your aimpoint adjustment would be minimal.
Cheers
Ruger7mm

hum... at 0deg both Hornady and Ballistic AE give me 1.28 mil at 260m. At 0deg these two app give me bang on the same table, no issue there. They also seems super accurate a 0deg. See below picture my zero at 100m for a new load then went 1.69 mils up and shot this group at 300m. Hornady app seems to get off track for some reason when angle increase.
What app are you using @Ruger7mm

point and shoot.....job done.

Originally Posted by Micky Duck

point and shoot.....job done.

Oh fuk yea. At that range down hill shot I've never taken any ballistic measurements, just centre cross hairs click bang dead deer. Obviously not head shots but broadside it's a big target.

Na I need the accuracy I like to eat fawn

Originally Posted by tibo

Na I need the accuracy I like to eat fawn

Ive shot hares with .270 between 400-500yards downhill...much further than Ive shot at big game....its surprising how little a bullet drops....rough guide is you use same drop as if you were shooting to spot out in direct line horizontally to above the animal.fawn sure tastes good,poke bullet into the crease.its still a 6" target area.