hit probabiltity at extended ranges

jerry1

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Dec 27, 2009
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What I would like to know is the hit probabilty of the various cartridges in question. Has anyone ran a test on a given target at say, 1100.1300, and 1500 yards (meters, whatever). I would like the data from .308, 300WM, and the .338 Lapula. Five five shot aggregates would be nice. To me that is the only data that is important. If someone would like to throw in a 6.5 or a 7Mag all the better. I enjoy reading opinions from people with far more military information than I have. However, these subjects seem to turn acrimonious in a hurry. If anyone has any data on actual hit probabilty I would appreciate it.
 
260shooter
You are exactly right. His book completely slipped my aging mind. I even own the book. I asked Mr. Litz if he was willing to share the software because there are many interesting questions to be explored. He is busy and did not get back to me. When I read the various claims about this caliber vs. some other caliber I often wonder where the evidence is to support that claim. I assume that shooters that champion a caliber have a rifle of that caliber. Why is it so hard for a shooter to run some tests and share the data. Then we would have some real world results. Thanks for your imput.
 
Posted this in the wrong spot

There is a ton that goes into hit probability at extended distances, anything beyond 1000 yards. Having shot a better than fair amount at distance, on actual targets and not rocks and things on the side of a hill. I can tell you there is a lot of variables to consider.


The bullet choice, and muzzle velocity are just one part. (what most books talk about) Anything below 1300fps things go down hill rapidly. Predictability becomes questionable at best. You can model it, and say bullet X is better than bullet Y, but that doesn't tell the whole story. What is written in specs and on paper doesn't always translate to success in the real world. I have read one too many "advertisements" of great BCs then when we put the bullet to paper like we did at Gunsite recently, we see some never make it, others hit sideways. Yes we shot on paper at 1500m and the results hardly matched the hype in a lot of cases. People read, Bullet X is the best choice and then Bullet X lands sideways when we actually tried it.


The field conditions, terrain, wind, all play a major part of it. You cannot gauge the wind to within the necessary 1 MPH. Without that, your round isn't hitting, you can recite Spindrift numbers, CE factors, and it's all meaningless if you can't properly dope the wind. Beyond 1500m I use 1/2 of what the computers say, and inside 1500 don' t use any of the factors. In fact I keep that crap turned off and hit better than most. go figure.


The shooter, huge factor, consistency from shot to shot is crucial, any errors are magnified and not just by 1 MOA per 100... it multiplies by factors greater than 1. Closer to 2x per 100 after 1000. Sure a broken clock gets it right twice a day, but that is not what we are talking about.


If you cannot hit the target, personally, within 3 shots under any condition, your hit probability is 0 in my book. If it takes more than 3, you need to re-evaluate your training and work up. If you fired 20 shots at a target and only impacted 5 times, you failed. Pick a new bullet, new caliber, increase your muzzle velocity or take a class on the fundamentals of marksmanship. It's that simple.


To shoot the XLR Class at Gunsite, (a great example, and great training opportunity) you spend at least 3 days, truing your software, working up to distance and managing your shots so you can hit targets beyond 1500m. You start at 300m then go to 600, 800, 1200, and beyond. All with targets designed to help you manage the shots. Targets with watermarks so you can see if you are hitting high or low your intended point of impact. Muzzle velocity variations at distance can mean a miss from shot to shot so you need single digit SDs, your load now matters.


When people talk hit probability it usually means, 1st round hits... well here is the real world.


308 is an 800m cartridge under the best conditions. Sure you can use a 30"+ barrel, push a 155gr bullet to 3150 and it will work well to 1000 yards, but that is not field practical.


A 300WM is a 1250m cartridge, yes we have new bullets, and better powders, so you can see greater success, but practically speaking that is the rule of the thumb.


338LM is a 1500m cartridge, yes we can do very well with it beyond, but after 1500m even under great conditions, 2 to 3 rounds is minimum for any kind of measurable success.


That is on man sized targets. if you want to put a 6ft x 6ft target out there, then your hit probability will go up, but if you are talking in the field, Man sized at the most, the above is practical. Don't believe me, go out and shoot it for real, on targets and record every single round. The results may surprise you.
 
Thanks to everyone who posted their thoughts. I have shot several thousand shots through a 300 Win using a serious rail gun set-up. Human error was nil. Past 1000 yards the number of hits was not impressive. A 40% hit ratio on a 15 inch target was a good day. Some days higher but a lot of days lower. I used 220 gr. SMK. I could get 2850 fps pretty easily. This is an excellent bullet and certainly a big step up from the .308. Lowlight is being very factual from my experience. It only takes an angels kiss in wind to cause a serious miss. There is a vast difference between shooting rocks vs. paper. The hits on rocks always seem dead on but the rock is usually a great deal larger than we think. Paper has no mercy. Reality is right in front of you. I have shot a lot of rocks and of course it is easy and fun. If the goal is "one shot one kill" then on the average we need to get a lot closer to our target. Those of you who have put your lives on the line have my full respect. I knew an older shooter from the state of Pennsylvania who was a member of a significant group who took deer at long ranges. Their tactic as explained to me was to range the deer and find a rock or clear aiming point to the right or the left of the animal. They took a shot and then swung back to the deer with the corrected dope. Apparently the deer did not pay much attention to an impact that they often could not see. I know they were quite successful. In that era the Barr&Stroud (sp?) was what they had. I repaired a number of those optical rangefinders (one meter baseline) and they were not bad. He never mentioned any ballistic software. They kept good notes and took their dope from actual targets. These men stayed at one stand for several days or until they got their deer. They shot from benchs and with rifles that would not be practical for any other use. In my experience the difference between calibers of the same class is small. Take a few extra clicks and you were there. While there are some advantages in theory the actual results are not so vast. Thanks again.
 
Forgive my naivete in most things ELR, but I have had a few experiences that may prove relative. Mostly confirming LL's comments about inconsistencies being twice or more as detrimental to POI. Last weekend, I was shooting 1840yards, conditions were around 8500ft, 60F, with winds moving left and right in about three different plains between me and the target at speeds varying between calm and maybe 10mph. Ballistic told me it would take 22.5MIL to get there with my .260 shooting 140VLD's@2940fps, but as Frank mentioned, I dont pay near as much attention to the BC at these ranges, its more of a get me close (its just a phone app, I wouldn't expect it to be perfect). First shot hit 1.5 high and about .8 right, so I corrected the elevation and held the wind. The next 6 or 7 shots were all very close, the target was a 14" steel disc (optimistic I know :D ) But the vertical was very minimal, definitely within the boundaries of the target, the shifting winds kept me moving back and forth probably as much as 1.5 feet in either direction, but several were right close. Had I been shooting at a larger target I think I would have gone probably about 40-50% but as it was I only hit it once. I didn't even know I hit it till I went to pick up my steel.

The wind got worse as I continued, so I swapped the .260 barrel for the 7SAUM in the hopes of doing better, but it just got worse, so I quit wasting ammo and came back to more realistic ranges for the conditions (600-1100)

Thats the target, under the zero:

 
Coldboremiracle
Your experience with keeping track of your shots is very relative. Like gamblers we tend to forget our losses. In response to Supergyro, if the rifles shot right at half-minute at closer ranges then one is comparing apple to apples fairly well. Naturally a poor rifle or a poor shooter reduces hit probability. Of course, the larger the target the greater the probability of hitting it. I hope to go to the Gunsite classes if I can swing it financially. I am sure it is a true eye-opener and a great time. Many times there a great topics on this site. I would like to see more data when each of us go out to shoot. If one takes 10 shots at 1250 yards/meters tell us how you did. Give whatever particulars that you have: scope, rifle, caliber, bullet, range, target size, fps and whatever else one may have. No-one has to be a great scientist to take and share data. By knowing your hit probability you have something to judge with before you take the shot. You might want to pass the shot or take it. Most days I learn or ponder something new. Often from this site. The day that one thinks they know all then that is the day his/her learning is done. Thanks again.
 
Forgive my naivete in most things ELR, but I have had a few experiences that may prove relative. Mostly confirming LL's comments about inconsistencies being twice or more as detrimental to POI. Last weekend, I was shooting 1840yards, conditions were around 8500ft, 60F, with winds moving left and right in about three different plains between me and the target at speeds varying between calm and maybe 10mph. Ballistic told me it would take 22.5MIL to get there with my .260 shooting 140VLD's@2940fps, but as Frank mentioned, I dont pay near as much attention to the BC at these ranges, its more of a get me close (its just a phone app, I wouldn't expect it to be perfect). First shot hit 1.5 high and about .8 right, so I corrected the elevation and held the wind. The next 6 or 7 shots were all very close, the target was a 14" steel disc (optimistic I know :D ) But the vertical was very minimal, definitely within the boundaries of the target, the shifting winds kept me moving back and forth probably as much as 1.5 feet in either direction, but several were right close. Had I been shooting at a larger target I think I would have gone probably about 40-50% but as it was I only hit it once. I didn't even know I hit it till I went to pick up my steel.

The wind got worse as I continued, so I swapped the .260 barrel for the 7SAUM in the hopes of doing better, but it just got worse, so I quit wasting ammo and came back to more realistic ranges for the conditions (600-1100)

Thats the target, under the zero:


Coldbore

Hitting a 14" target at 1840 in no wind condition with a 260 is good shooting in anyone's book, so in windy condition, it just kills it; especially with changing winds. Just depends on how lucky you are on that day. The 7 SAUM should have been better but...
We all had reality check from time to time; keeps us humble, as we are only as good as our last shot.
The only ones who never fail are the ones never trying anything, betcha you will nail that target next time.
Good shooting ;)
 
I believe he was saying that we to often only talk about the hits, disregarding all the misses.
Several times I have hit very close to the target @ 1950 yds on my CB shot quickly corrected, & hit the next 1, or 2 shots then the wind changed, or mirage started running, & wasted 10 more not even seeing where they went. I like to remember the ones that hit not the ones that missed. That is with my 300WM.
 
I believe he was saying that we to often only talk about the hits, disregarding all the misses.

Thats the impression I kinda got as well, which is a strange thing to say considering I called zero hits, only misses. It was only after retrieving the target that I found the hit on the plate. I find no value in dismissing a miss, or misrepresenting a hit.
 
I believe he was saying that we to often only talk about the hits, disregarding all the misses.

Thats the impression I kinda got as well, which is a strange thing to say considering I called zero hits, only misses. It was only after retrieving the target that I found the hit on the plate. I find no value in dismissing a miss, or misrepresenting a hit.
 
There are not many competitions shot beyond 1000 yards but earlier this year I competed in a F-Class competition at 1500 yards.
This gives a very good representation of what is possible with top class gear and experienced National level shooters.
Total score was out of 270 points.
45 shots in total with max of 6 points for a centre bull. The X is also worth 6 points and is 1/2 the size of the centre bull.
X count is used to break ties.

Centre is 16" in size and X is 8" in size.
Shooting conditions was good but with a with light switching fishtail wind.
Rifles were mostly 7mm SAUM's and .284's etc Most of the Magnum 7mm's are at the top of the score board and the .284's etc down the bottom.
Below are the scores for the 14 competitors. Make of it what you wish............. Full results here....... http://www.matchrifle.org/Results_Australia/Results_PDF/Coonabarabran 1500 yds_2013.pdf

.308's were also used in a different class and their scores were way down but still impressive I think. Check the link above for their results.


253, 7

251, 11

251, 7

245, 10

239, 7

238, 4

237, 8

237, 6

236, 4

234, 6

234, 3

234, 2

227, 6

220, 2
 
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I think that if luck is a significant part of one's strategy, one will dessert on frustration.

Go back and reread LL's narrative; he speaks reality/experience, and his reality/experience trumps most others on this site, mine most certainly; I've seen him do what he does. In his place, I'd be thrilled to accomplish a hit probability, with his equipment on his range, of as much as 1/3 of his achievement. Wind skills and experience are that important, and without them, luck becomes the dominant factor.

For the most part, one needs to develop capabilities incrementally, building experience and skill on a solid foundation. If you're not doing it at 500, there's little to support a serious effort at 1000, and so on. There will come a point, probably different for each shooter, when the LR process becomes one of learning one's limits and working within them. Very simply, it then makes better sense to move in on the target than to try and squeeze one's skills through knotholes trying to do what one has already failed to prove is possible for them.

Some years back, I would shoot 1000yd F Open Class twice each month with a custom built .260. I would consider my scores then as a highly optimistic example of a personal hit probability of 90-85%, and that wasn't even putting me in the top ten competitors. The part about not being mindful of one's other shots bears directly on the 'unlimited sighters' that are not counted as part of that score. Factor them in, and the hit probability drops back to about 70-80%, first hit probability hovers right around zero; and the other competitors are still whippin' my butt....

That's reality.

Greg
 
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Greg you are not the only one getting your butt whipped. Most do at ELR distances.
Its interesting to see how things deteriorate with a drop in gear performance, skill level or target size.

Have a look at the top five shooters above. They averaged 8.4/45 hits on that 8" X ring at 1500 yards during the days comp. The bottom five averaged 3.8/45 hits.
Now the scores were not too bad so there was obviously a much greater number of hits on the 16", 6 ring for each shooter. So size does matter.

Another thing that had a great effect was just where the bullets were going transonic. My bullets were getting there at about 1200 fps and my scores were lower than the magnums that were getting there at over 1400 fps. I was loosing quite a few points to vertical dispersion where as they still kept a reasonable water line even though a lot of us were using the same 180gn Berger bullets.
 
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Key words,

top gear = expensive and not practical

7mm is a great bullet and I explained that, bullet selection matters, along with MV. How many of the Top rifles have barrels longer than 28"? Bet the muzzle velocities were over 3000fps probably over 3100fps.

Practical is subjective in this case, carrying your rifle from the car to the line is not what we are talking about.

Now push that 7mm to 1800 and see the differences, I have a 7WSM and have shot it to 1760 and it worked. I have also seen a 2nd round hit at 1997 with one, after two guys shot before and doped it. Remember, 1500 yards is not 1500m these differences matter, especially when not using Top Gear. 99% of the shooter out there don't have top gear. Reduce the barrels to 25" or below and see what happens. Engineering races are great launch points but hardly real world.
 
encouragement to keep track of ALL data that can be used to learn more.

Very true, I always tell myself; if you dont know why you are missing, your wasting your time. Thats why I am always trying to figure out why a bullet went where it did, and if I cant figure it out, I quit wasting precious ammo until such a time that I can figure it out.
These threads are very helpful and educational, thanks be to those that keep them afloat, and enriched with both data and insight, and the wisdom to interpret them.
 
A bunch of us ELR shooters are getting together this weekend for a field shoot. Not sure what rifles will be there yet but a good cross selection I would say.
Distances will be out to a max of about 2200 yards.
I will try and keep a record of what sort of success the shooters have with first round hit probability and also the number of rounds taken to get onto target at the various distances.
Should be interesting.
 
wadcutter, in this "sniper" context a true first shot should not be influenced by the observation of the impacts of the guy next to you in the firing line, or conversation with all observers... just saying :)

It would be very interesting to see a bunch of team of sniper + spotter teams get in place with no imput from other people, and record their shots.
 
Contrary to how the Magpul video comes across in places , in the actual Accuracy 1st course, the instructor was VERY realistic about first-round hits at distance. He had a ton of real world knowledge on the 2-way range and was honest about all the "one round hits at a mile" being bullshit, even with a .50.
He said that across their courses, where most shooters are attempting the mile shot for the first time, they see the following "averages":
.308 ~25-30 rounds fired for a hit
.300WM ~10-15
.338 ~5-8

Targets are either the Acccuracy 1st steel or IPSC stye steel (I have the measurements in my data book which I don't have with me).

I'm going from memory on those exact stats, but if I'm off by one or two I don't think it's significant.
In the course I attended those numbers were pretty well born out. Most of us with .308s quit wasting ammo before the 30-miss mark. The one guy with a .300 quit after 10-15 misses dancing from one side of the target to the other. One guy broke out a .338 solely for the mile shot and did in fact hit about round #4 or 5 or so.

It was a great eye-opening course to get an idea of what was and was not realistic with our respective setups.
 
Well we had two days of shooting.
First day was horrendous winds up to 35mph. Shooting at 1525 yards was ok with the wind at our back. Most guys got onto target within three shots with .338 Laps and .375 Cheys. Smaller stuff had trouble.
Then went to a full cross wind at 1915 yards and with 16 to 20moa of wind on it was interesting to say the least. No first round hits! But a couple out of about 10 shots per rifle.
Next day it was better conditions and we shot out to 1400 yards. 7 to 8 mph cross wind. A few first round hits on 2 moa size targets and plenty with all rifles after a couple of shots.
 
I love the reality check the information in this thread provides and who it is coming from.

It amazes me how many opinions are out there on ELR/LR shooting and what a particular round will/will not do, it is good to see those who are an authority on the matter chime in and hopefully this information sinks in with a lot of readers and helps to debunk a lot of the myths you see come up in discussions here quite regularly that fuel those myths.

Thanks, fellas, for the good info!