phil mcwilliam
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Just aim higher.
My 1,000 Yard Mission
- Thread starter Tangentabacus
- Start date
Theres lots of good information in this post regarding practice and not equipment. Too many times people dump all their available funds into glass or bipods or whatever and forget that the best tool is practice / experience. Thanks for sharing useful information and not letting this turn into a equipment debate.
I have a question regarding long-range and caliber - The two rifles I want to use to go for 1000yd are an older 30-06 sporter and a relatively new 22-250 with bull barrel and a heavy stock. I've shot the 22-250 out to 385 yards checked using a rangefinder, and it's definitely accurate, and I'd expect it to remain supersonic at 1000, considering muzzle velocity starts at 3600-4000fps.
My question is, is a 22-250 a reasonable caliber to shoot at this distance, what with the lightweight bullets that may not buck the wind at extreme ranges as well as a .308 bullet that weighs 100-120 grains more?
My question is, is a 22-250 a reasonable caliber to shoot at this distance, what with the lightweight bullets that may not buck the wind at extreme ranges as well as a .308 bullet that weighs 100-120 grains more?
I wouldn't make that assumption. The light .224s suitable for the slow twist barrels found on factory .22-250 rifles have fairly low Ballistic Coefficients, and shed their velocity in a hurry.
Running the numbers, a Sierra 50 gr BlitzKing starting at 4000 fps is subsonic before 800 yards (~780)
Yeah, if you have a custom fast twist barrel, you could shoot the heavy target bullets, but frankly if you are putting on a custom barrel, there are probably better choices.
That being said, you can try it. Some bullets handle the supersonic to subsonic transition better than others, you may find your load works.
^^^
This.
With an 8 twist and 80 grain bullets it would do the job...
But if you have a 14 twist and are limited to the 50 grain bullet with a lousy BC it's going to be an uphill battle.
Reasonable?
That's in the eye of the shooter. There are guys that like to shoot VLD .223's to 1000 yards. Not my cup of tea, though...
This.
With an 8 twist and 80 grain bullets it would do the job...
But if you have a 14 twist and are limited to the 50 grain bullet with a lousy BC it's going to be an uphill battle.
Reasonable?
That's in the eye of the shooter. There are guys that like to shoot VLD .223's to 1000 yards. Not my cup of tea, though...
If one checks the ballistics of bullets fired from .308 win. cases in 24 to 26 inch barrels, they'll see the following trajectory data for a 1000 yard zero:
Bullet drop at 1000 yards ranges from about 420 to around 480 inches; your sight will need 42 to 48 MOA elevation from boresight to zero at 1000 yards. Most bases and rings for a given receiver are set to put the scope's mechanical axis parallel to the receiver axis. The bore axis may well be off by several MOA. So your scope needs to have at least 50 MOA elevation up from optical zero in the scope if you want to use the same setup for ranges from 100 to 1000 yards. Or, use a 20 to 30 MOA angled base. Don't shim a rear base; that'll put the ring axis on it above the front ring and sometimes bends scope tubes when they're clamped in hard. One other thing, optical zero in the scope's probably not half way between the E and W adjustment limits. You can find the scope's optical zero by spinning it in two V blocks then adjusting E and W until the reticule stays on the same point as the scope goes round and round.
Highest point in the trajectory is about 12 to 13 feet at around 600 yards. Winds up to 12 feet above ground are fairly even in speed. The wind closest to the firing point has the greatest effect at the target. So pay close attention to the wind for the first 300 yards where the bullet's under 10 feet above the line of sight.
Bullet drop at 1000 yards ranges from about 420 to around 480 inches; your sight will need 42 to 48 MOA elevation from boresight to zero at 1000 yards. Most bases and rings for a given receiver are set to put the scope's mechanical axis parallel to the receiver axis. The bore axis may well be off by several MOA. So your scope needs to have at least 50 MOA elevation up from optical zero in the scope if you want to use the same setup for ranges from 100 to 1000 yards. Or, use a 20 to 30 MOA angled base. Don't shim a rear base; that'll put the ring axis on it above the front ring and sometimes bends scope tubes when they're clamped in hard. One other thing, optical zero in the scope's probably not half way between the E and W adjustment limits. You can find the scope's optical zero by spinning it in two V blocks then adjusting E and W until the reticule stays on the same point as the scope goes round and round.
Highest point in the trajectory is about 12 to 13 feet at around 600 yards. Winds up to 12 feet above ground are fairly even in speed. The wind closest to the firing point has the greatest effect at the target. So pay close attention to the wind for the first 300 yards where the bullet's under 10 feet above the line of sight.
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I disagree with that. The wind has the most effect on the bullet at half to two thirds distance the target. That is where the bullet is at it's highest arc and where its most directly into a "full value" wind effect.
Take your range flag, hang it at 30 ft, or at the top of the pole. Take a second flag and hang it on the pole at barrel level. You'll see the wind is completely different at 30 ft and ground or barrel level. The bullet would be more effected at its highest arc more then at the barrel or shooting level.
This chart explains it a bit better. We know a partial value of wind has less effect then a full value. The chart shows what part of the bullet's flight that is in the "full value" of its path.
Sierra Bullets Ballistic Software used to calculate the following for a .300 Win. Mag. cartridge:
Drift at 900 yards for wind only in the last 300-yard segment's about 1/3rd of what wind only in the first 300-yard segment.
For wind only in the middle 300-yard segment, drift at 900 yards is a little more than twice what wind only in the last 300-yard segment has at 900 yards.
The bullet's drift rate increases with range but the distance to the target gets less with each range band further down range.
Reading the mirage through a spotting scope will reveal the wind at the top of the bullet's trajectory moves at the same speed as it does in the line of sight. The wrinkles high and low all have the same speed; they move together. If the wrinkles at the high point of the trajectory did move faster than the lower ones, it would be easily seen.
Normal come up on M1 and M14 sights going from 600 to 1000 yards is about 23 clicks/MOA for .308 Win. ammo. At 600 yards, that moves the bullet trajectory up about 12 feet at 600 yards; the average high point in its trajectory to 1000 yards. The wind atop a 30 foot pole is over 15 feet higher than the bullet's path; it doesn't effect the bullet at all.
Drift at 900 yards for wind only in the last 300-yard segment's about 1/3rd of what wind only in the first 300-yard segment.
For wind only in the middle 300-yard segment, drift at 900 yards is a little more than twice what wind only in the last 300-yard segment has at 900 yards.
The bullet's drift rate increases with range but the distance to the target gets less with each range band further down range.
Reading the mirage through a spotting scope will reveal the wind at the top of the bullet's trajectory moves at the same speed as it does in the line of sight. The wrinkles high and low all have the same speed; they move together. If the wrinkles at the high point of the trajectory did move faster than the lower ones, it would be easily seen.
Normal come up on M1 and M14 sights going from 600 to 1000 yards is about 23 clicks/MOA for .308 Win. ammo. At 600 yards, that moves the bullet trajectory up about 12 feet at 600 yards; the average high point in its trajectory to 1000 yards. The wind atop a 30 foot pole is over 15 feet higher than the bullet's path; it doesn't effect the bullet at all.
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I have no knowledge of whether the wind is more consistent near ground level, or higher as is being discussed.
But seems that discussion is relevant to the "wide open spaces", and not high-berm, enclosed shooting like the 1000 yard range we frequent.
The high berms cause confusing, swirling winds...like being down in a punchbowl.
The last 400 yards (beyond the 600 yard berm) is called the "ditch"- because it's literally that- a 400 yard narrow ditch surrounded by high berms.
Completely different wind effects...a real challenge
http://manateegunclub.com/index_files/SateliteView.htm
But seems that discussion is relevant to the "wide open spaces", and not high-berm, enclosed shooting like the 1000 yard range we frequent.
The high berms cause confusing, swirling winds...like being down in a punchbowl.
The last 400 yards (beyond the 600 yard berm) is called the "ditch"- because it's literally that- a 400 yard narrow ditch surrounded by high berms.
Completely different wind effects...a real challenge
http://manateegunclub.com/index_files/SateliteView.htm
David Tubb is probably one of the best long range shooters this country has ever produced.
He is the one that demonstrates using the range flags to show where the wind is most effective. He simply does what I mentioned earlier. A flag pole is about 30 feet tall. He puts a flag at the top of the pole and one at the bottom, the wind speed is normally different, and may be even blowing a different direction.
Even on flat ranges there is going to be something on the ground to disturb the wind.
Just ask yourself why the Army Marksmanship Unit, and everyone else experienced in long range shooting tell you to focus your scope at Midrange to 2/3 range, to read mirage and other wind indicators.
To see what wind really does, you can put the numbers in a BC program OR you can go to the range with a good spotting scope and see for your self.
Get right behind the shooter and observe the trace of the bullet, on a full value wind coming from 3 o'clock, you see the bullet start our toward the right and when it gets past mid range starts a sharp turn back toward the target, much like the picture I posted above.
At 1000 yards, (which is what the OP asked about) the 308 arc is between 30-35 ft above the ground.
That is the wind you should concern yourself with the most.
As to hand held wind meters. They are great, but not for what people think.
People take a reading on the firing line, and that's what they use to adjust their sights. But that isn't the wind they should be reading. They should be reading the wind at the height of the arc.
Thats where mirage comes in if there is no range flags.
To learn mirage is where the wind meter comes in. Go to the range or open field, leave your rifle home, and take your spotting scope and wind meter.
Get a reading (doesn't matter where) then look through the scope and see what the mirage is doing. What you are trying to do is learn what the mirage does at different wind speeds. You can do this at different angles to get the ideal of the mirage at different values. It doesn't matter how high off the ground, air movement is what you're looking at so you can get an idea of what mirage looks like at different wind speeds.
You do this a bit, then when shooting, you can focus your scope at 1/2 - 2/3 distance to the target at the max arc of what bullet you are shooting and get the best reading of the wind (mirage) to get you on target.
Here's a hint about focusing the scope and reading mirage, Be careful you don't go the wrong way. Meaning be careful you don't focus the scope past the target. Doing so will reverse the mirage.
I found this out the hard way when I attended the NG-MTU Coaches Clinic.
We were on 600 and the ALL Guard Shooters were taking our call. In other words they were making the corrections we were giving them, right or wrong.
After the targets were run up, showing the hits, I was on the opposite side of everyone else. Because I was focused beyond the target the mirage was reversed.
I don't have to tell you how embarrassed I was when shooting was stopped and the whole line of future coaches was brought to my point to be shown WHAT NOT TO DO.
He is the one that demonstrates using the range flags to show where the wind is most effective. He simply does what I mentioned earlier. A flag pole is about 30 feet tall. He puts a flag at the top of the pole and one at the bottom, the wind speed is normally different, and may be even blowing a different direction.
Even on flat ranges there is going to be something on the ground to disturb the wind.
Just ask yourself why the Army Marksmanship Unit, and everyone else experienced in long range shooting tell you to focus your scope at Midrange to 2/3 range, to read mirage and other wind indicators.
To see what wind really does, you can put the numbers in a BC program OR you can go to the range with a good spotting scope and see for your self.
Get right behind the shooter and observe the trace of the bullet, on a full value wind coming from 3 o'clock, you see the bullet start our toward the right and when it gets past mid range starts a sharp turn back toward the target, much like the picture I posted above.
At 1000 yards, (which is what the OP asked about) the 308 arc is between 30-35 ft above the ground.
That is the wind you should concern yourself with the most.
As to hand held wind meters. They are great, but not for what people think.
People take a reading on the firing line, and that's what they use to adjust their sights. But that isn't the wind they should be reading. They should be reading the wind at the height of the arc.
Thats where mirage comes in if there is no range flags.
To learn mirage is where the wind meter comes in. Go to the range or open field, leave your rifle home, and take your spotting scope and wind meter.
Get a reading (doesn't matter where) then look through the scope and see what the mirage is doing. What you are trying to do is learn what the mirage does at different wind speeds. You can do this at different angles to get the ideal of the mirage at different values. It doesn't matter how high off the ground, air movement is what you're looking at so you can get an idea of what mirage looks like at different wind speeds.
You do this a bit, then when shooting, you can focus your scope at 1/2 - 2/3 distance to the target at the max arc of what bullet you are shooting and get the best reading of the wind (mirage) to get you on target.
Here's a hint about focusing the scope and reading mirage, Be careful you don't go the wrong way. Meaning be careful you don't focus the scope past the target. Doing so will reverse the mirage.
I found this out the hard way when I attended the NG-MTU Coaches Clinic.
We were on 600 and the ALL Guard Shooters were taking our call. In other words they were making the corrections we were giving them, right or wrong.
After the targets were run up, showing the hits, I was on the opposite side of everyone else. Because I was focused beyond the target the mirage was reversed.
I don't have to tell you how embarrassed I was when shooting was stopped and the whole line of future coaches was brought to my point to be shown WHAT NOT TO DO.
Kraig says:
If what you say's reality, then please explain why coming up 23 to 24 MOA from a 600 yard zero to a 1000 yard zero puts bullets from a .308 thirty feet or more above the 600 yard target when 23.5 MOA at 600 yards equals 11.75 feet. Download Berger's software and see for yourself.
I already know all that other stuff you mentioned. And more than a few of us High Masters in NRA long range matches have confronted David Tubb about his areas of ignorance.
Fine. How do you suggest all the ballistic software out there get changed to do that? Berger's and Sierra Bullet's software is probably the best available. They put the maximum ordinate for .308's zeroed at 1000 around 12 feet near 600 yards.
If what you say's reality, then please explain why coming up 23 to 24 MOA from a 600 yard zero to a 1000 yard zero puts bullets from a .308 thirty feet or more above the 600 yard target when 23.5 MOA at 600 yards equals 11.75 feet. Download Berger's software and see for yourself.
I already know all that other stuff you mentioned. And more than a few of us High Masters in NRA long range matches have confronted David Tubb about his areas of ignorance.
Maybe we aren't on the same sheet of music.
I do use Berger's program, and if you use a 1000 yard zero (which you would be using if you're shooting 1000) the highest arc of the bullet will be about 600 yards, and that is where you should be reading the wind when shooting 1000 yards.
The flag pole was used as an example to show you get a more accurate wind reading up in the air then you would at ground level.
Just forget the numbers, set your BC program with a zero at the range you're shooting. It will then give you the max arc, which will be about or just beyond mid range.
And that's why the AMU, and Tubbs recommend reading the wind/mirage at mid to two thirds distance down range.
I think we are bantering semitics.
I do use Berger's program, and if you use a 1000 yard zero (which you would be using if you're shooting 1000) the highest arc of the bullet will be about 600 yards, and that is where you should be reading the wind when shooting 1000 yards.
The flag pole was used as an example to show you get a more accurate wind reading up in the air then you would at ground level.
Just forget the numbers, set your BC program with a zero at the range you're shooting. It will then give you the max arc, which will be about or just beyond mid range.
And that's why the AMU, and Tubbs recommend reading the wind/mirage at mid to two thirds distance down range.
I think we are bantering semitics.
Kraig, here's what I set Berger's software to:
Standard defaults used except as follows.....
Zero and max range at 1000 yards, range increment at 10 yards.
Bullet at .308 diameter, 175 grains, G1 BC at .490 (for Sierra's 175 HPMK), muzzle velocity at 2650
Highest bullet's trajectory above line of sight happened at 570 yards with 142.96 inches above line of sight. That's 11.91 feet.
Use these inputs with your Berger software and we'll compare notes. Maybe those "notes" will be good for the "music" we're discussing while bantering semantics.
You can also use Berger's software to see why wind closest to the firing line has the greatest effect on drift at the target. If you trust Berger's software to be accurate.
Standard defaults used except as follows.....
Zero and max range at 1000 yards, range increment at 10 yards.
Bullet at .308 diameter, 175 grains, G1 BC at .490 (for Sierra's 175 HPMK), muzzle velocity at 2650
Highest bullet's trajectory above line of sight happened at 570 yards with 142.96 inches above line of sight. That's 11.91 feet.
Use these inputs with your Berger software and we'll compare notes. Maybe those "notes" will be good for the "music" we're discussing while bantering semantics.
You can also use Berger's software to see why wind closest to the firing line has the greatest effect on drift at the target. If you trust Berger's software to be accurate.
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I used the 175 @ 2550 (my M1A or 308 target rifle I use) and the altitude for my area (4500 Ft). Which gets us pretty close to the maximum ordinate of the 308 shooting at 1000 yards which is just beyond mid range.
Which I believe is the point at which wind has the most effect.
Of course different bullets and different velocities means a different max ordinate but they are pretty much between mid and 2/3s range to the target.
We talk about wind effects but the most critical is in overhead fire. (Where you are covering advancing troops)
To figure the abscissa (distance from the gun to the ordinate we need to know the ordinate in mils, its value in yard to determine the max ordinate.
The Formula is W=R*M/1000
Where is R = the abscissa
M = the difference of angle of departure in mils between the abscissa and the target
W is the max ordinate.
I had to teach this when running machine gun schools teaching overhead fire to determine the safe areas between the gun and the target.
Lets say we are using the 150 grn 30 cal bullet at 2700 fps (typical machine gun ammo.
The angle of departure for 1000 yards would be 14.047 mils
The angle of departure for 600 yards would be 6.009 mils.
14.047-6.009 = 8.018 mils
600 * 8.018/1000 = 4.810 yards or 14.43 feet
do the numbers for the for 700 and 800 yards (angle of departure is 7.598 and 9.443 respectively) you'll find in this case the max ordinate between the rifle and target is at 700 yards or about 16 feet,
7/10s is still pretty close to 2/3s distance.
If you don't have a method of determining angle of departure in mils remember 17.7 mils in degree or 3.437 minutes in a mil.
Yap you can get the same thing from a BC program, but we didn't have such programs (or computers) when I was in the game.
The point being the above math will check your BC program AND confirm the max ordinate will be between 1/2 and 2/3s distance between you and the target. And that is where you get the most effect of the wind.
I know a lot of this seems off topic but in reality it isn't.
We had this problem come up on our clubs range. The power company put some power lines across our range. We had to set our 300 yard targets where the max ord. of pretty much any round wouldn't hit the power lines.
Using the math posted above, shows that since the power line is less then half way between the firing line and the 300 yard line, we could shoot rounds with a max ordinate that exceeded the height of the power lines. Rifles werent the problem but pistols and BPCRs were.
Back to wind, get your values from 1/2 to 2/3s distance between you and the taget for the most accurate reading.
Which I believe is the point at which wind has the most effect.
Of course different bullets and different velocities means a different max ordinate but they are pretty much between mid and 2/3s range to the target.
We talk about wind effects but the most critical is in overhead fire. (Where you are covering advancing troops)
To figure the abscissa (distance from the gun to the ordinate we need to know the ordinate in mils, its value in yard to determine the max ordinate.
The Formula is W=R*M/1000
Where is R = the abscissa
M = the difference of angle of departure in mils between the abscissa and the target
W is the max ordinate.
I had to teach this when running machine gun schools teaching overhead fire to determine the safe areas between the gun and the target.
Lets say we are using the 150 grn 30 cal bullet at 2700 fps (typical machine gun ammo.
The angle of departure for 1000 yards would be 14.047 mils
The angle of departure for 600 yards would be 6.009 mils.
14.047-6.009 = 8.018 mils
600 * 8.018/1000 = 4.810 yards or 14.43 feet
do the numbers for the for 700 and 800 yards (angle of departure is 7.598 and 9.443 respectively) you'll find in this case the max ordinate between the rifle and target is at 700 yards or about 16 feet,
7/10s is still pretty close to 2/3s distance.
If you don't have a method of determining angle of departure in mils remember 17.7 mils in degree or 3.437 minutes in a mil.
Yap you can get the same thing from a BC program, but we didn't have such programs (or computers) when I was in the game.
The point being the above math will check your BC program AND confirm the max ordinate will be between 1/2 and 2/3s distance between you and the target. And that is where you get the most effect of the wind.
I know a lot of this seems off topic but in reality it isn't.
We had this problem come up on our clubs range. The power company put some power lines across our range. We had to set our 300 yard targets where the max ord. of pretty much any round wouldn't hit the power lines.
Using the math posted above, shows that since the power line is less then half way between the firing line and the 300 yard line, we could shoot rounds with a max ordinate that exceeded the height of the power lines. Rifles werent the problem but pistols and BPCRs were.
Back to wind, get your values from 1/2 to 2/3s distance between you and the taget for the most accurate reading.
I think you're missing my point, regardless of heigth of the max. ord, it's still gonna be 1/2 -2/3s distance to the target. Whether its 2550 fps or 2650 fps. Whether its a pistol shoot 50 yards or a 260 Rem shooting 1000 yards.
Matters not whether you are using a BC program or math, the end result is the same as to where the max ord (what ever it is) will be pretty much the same 1/2 to 2/3s.
The Max Ord will be different of course, but the point of the max ord will be 1/2 to 2/3s distance to the target.
Matters not whether you are using a BC program or math, the end result is the same as to where the max ord (what ever it is) will be pretty much the same 1/2 to 2/3s.
The Max Ord will be different of course, but the point of the max ord will be 1/2 to 2/3s distance to the target.
Kraig,
Don't know that I agree about "useless."
The science behind what makes things happen is fascinating to me.
There are facts you use and those that are tucked away. I do agree more shooting is a real benefit. It is also nice to know why things occur the way they do.
I really do find your posts worth reading.
Don't know that I agree about "useless."
The science behind what makes things happen is fascinating to me.
There are facts you use and those that are tucked away. I do agree more shooting is a real benefit. It is also nice to know why things occur the way they do.
I really do find your posts worth reading.