Hitting the ground.

caorach

Well-Known Member
Some time back there was a posting on here which raised my interest, the person posting was mentioning that the bullet fired from his rifle would have hit the ground in several hundred yards over flat ground.

This evening I took a few minutes to see just how far a bullet from my 308Win would travel before it hit the ground. I made a lot of assumptions as follows: the muzzle was 5 feet from the ground, the zero was at 200 yards, it was a 150 grain Hornady Spire Point leaving at 2800fps, the target was level with the muzzle, (i.e. the rifle was tilted neither up nor down) the ground was perfectly flat etc.

However, the 60 inch drop happens in just about 520 yards under those rather artifical assumptions. Changing my zero to a 100 yard zero puts the impact at just over 490 yards so not as much difference there as I would have expected.

I guess this is of some interest to those who shoot over flat fields and the like and it is certainly of academic interest.
 
Probably quite handy to know these figures when you're trying to get your piece of flat ground cleared.
I wonder whether the angle of impact with the ground would be quite shallow and therefore more likely to result in a ricochet though:confused:

What did you use to work this out?
Mick
 
I was lazy and used the following:

http://www.jbmballistics.com/cgi-bin/jbmtraj_simp-5.0.cgi

Just got it to work out where the 60 inch drop would happen so a very simplified model of what actually happens, it is a good resource though for external ballistics. The angle will be very shallow, I was hoping to avoid any trig but it should be an easy calculation, as basically you are looking at a 60 inch drop in about 500 yards. It would be really interesting to know how a centre fire round behaves when hitting the ground under those circumstances as it will not have a huge amount of energy for deformation and the like. Also a lot of ground we shoot over is likely to be covered in heather and so it isn't just a case of hitting flat ground.
 
very interesting .It is probably around the range i thought but must admit i havent thought about the speed the round would still be travelling an how much it could ricochet
 
At 500 yds a 150 grn bullet will still be travelling at around 1770 fps and still have around 1050 ft.lb so still plenty of energy to ricochet i would say so really does bring the importance of a backstop into play at any range
 
Just a thought on the flat ground thing. Shooting at a muntjac standing, you are shooting down at it. A fallow, sika, off the elbows or harris bipod. You are elevating the rifle considerably. How far will your bullet travel then?
 
A few years ago I was responsibe for shooting deer in a park, the owner butchered them himself and sold the venison through the farm shop/markets.
All shots were taken about 40-60yrds from a vehicle, quite often after the first shot the deer would herd up {approx 80] so you'd wait a couple of mins and they'd start to graze again and you could pick out another animal and get another clear shot. Whenever possible I'd head shoot, and I used a moderated 243.

It was amazing after a few months in , I started to find shrapnel under the skin when skinning deer, and when watching them you'd see a beast looking a little under the weather, after skinning it you'd find small wounds.

After this I put up 4 high seats just to get a downwards angle and that seemed to stop the problem. I'm sure that when culling in big herds deer are inadvertantly getting wounded.

I've mistakingly killed 2 deer with one bullet has pass through one and hit another, I know plenty of others have had the same. The trouble is that once the bullet has hit it's first obstacle be it ground branch , deer it's impossible to tell what it'll do.

I remeber shooting seals out at sea in calm weather , you could shoot one and then seconds later you'd see a splash 100's of yrds behind, dangerous stuff it gave me one hell of a fright.

My brother once when spotlighting rabbits shot a rabbit out in front of the landrover , he hadn't taken account of the stone dyke behind the rabbit, the bullet bounced back and through the rover windscreen, he handed in his fac the next day and hasn't shot since[16yrs ago]
 
This reminds me of firing my .22 air rifle on a still piece of river (40 years ago). If the pellet struck first 50+ yds upstream, you could see it hit the water 3 or 4 times more out to ~400yds before it would finally hit the water and sink. The was a <12ftlb BSA Meteor.
 
Just a thought on the flat ground thing. Shooting at a muntjac standing, you are shooting down at it. A fallow, sika, off the elbows or harris bipod. You are elevating the rifle considerably. How far will your bullet travel then?

Assuming my 308 load and a target at 200 yards with the rifle zeroed at 200 yards and the target 3 feet above the muzzle with the muzzle on a bipod 9 inches above the ground then you are looking at hitting the ground at about 665 yards if my logic is correct.

That is a pretty long way if you don't have a backstop and, of course, as others have pointed out doesn't allow for any strange behaviour on the part of the bullet.
 
I was culling parkland fallow last year; shot one doe through the chest, the bullet exited at 45 degrees and dropped a second doe with a neck shot. I'm not sure how far a deformed bullet is likely to travel, but it certainly makes you think!
 
I'm not sure how far a deformed bullet is likely to travel, but it certainly makes you think!

I've no idea either but for a laugh I assumed that the bullet expanded to .6 of an inch, lost no weight and exited with half its velocity at 1400fps. I've no clear idea how to get a basllistic coefficient for a deformed bullet and so went with the shape of an airgun pellet, this might be very wrong indeed but it was my best wild guess. I also assumed it exited heading neither upwards nor downwards, a most unlikely situation. However, under these circumstances and assuming it exited the deer at 3 feet from the ground it would hit the ground in about 22 yards, not very far at all and not at all in keeping with the experience of many on here. It would, however, have 619ft lbs of energy on hitting the ground so enough to do quite a lot of work.

At 100 yards the drop would be 163 inches and there would still be 517 ft libs of energy.

This assumes that the logic of my calculations is correct which is unlikely even on a good day.
 
Brings to mind an incident few yrs ago, me and mate leant each side of the shelter upright @ Putley range, someone was shooting (we used to shoot practical pistol) a round came back up the range and stuck in the upright between our heads:eek::eek::eek:.
We moved !
Also saw a write up once saying that if an average sized bloke fired a .22 rifle level, the bullet would hit the ground at about 200 yds.
 
I dont get complacent with firearms or bullet flight but now and again something happens that make you take stock.
I recently shot a doe at about 100 yards, she was broadside on and standing a couple of yards in front of a large sycamore trunk. the bullet (.308 125grn) passed through her making the usual exit hole, and buried itself into the tree trunk so deep I could'nt feel it with the knife! I will dig it out when I get chance.
It just goes to reminds you just how much energy bullets have even when they have passed through bones and flesh.

Isnt that why the army stopped using 7.62 in northern Ireland, they found that bullets were passing through humans and continuing through brick walls into houses.
 
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