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Offline RUGER No.1

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« on: May 29, 2010, 01:00:25 PM »
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« Last Edit: February 15, 2011, 05:38:45 AM by RUGER No.1 »
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Offline FC

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Re: High Elevation Shooting
« Reply #1 on: May 29, 2010, 01:07:21 PM »
You will shoot noticeably flatter at that height, if possible check your sights at practical range before actually hunting but only if you are shooting at upper end ranges for caliber. With what you guys are working with I wouldn't worry about it unless you are planning on taking 400+ yard shots as the differences due to altitude would be minimal at that range.
The reason there are so many Ruger upgrades is because they're necessary.

Offline rasbo

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Re: High Elevation Shooting
« Reply #2 on: May 29, 2010, 01:10:55 PM »
Bullet Flight, Altitude and Air Pressure
Filed under: Bullets, Brass, Ammo — Editor @ 1 pm
One of our readers asked “What effect does altitude have on the flight of a bullet?” The simplistic answer is that, at higher altitudes, the air is thinner (lower density), so there is less drag on the bullet. This means that the amount of bullet drop is less at any given flight distance from the muzzle. Since the force of gravity is essentially constant on the earth’s surface (for practical purposes), the bullet’s downward acceleration doesn’t change, but a bullet launched at a higher altitude is able to fly slightly farther (in the thinner air) for every increment of downward movement. Effectively, the bullet behaves as if it has a higher ballistic coefficient.

Forum members Milanuk and Catshooter explained that the key factor is not altitude per se, but rather air pressure. Milanuk writes:

“In basic terms, as your altitude increases, the density of the air the bullet must travel thru decreases, thereby reducing the drag on the bullet. Generally, the higher the altitude, the less the bullet will drop. For example, I shoot at a couple ranges here in the Pacific Northwest. Both are at 1000′ ASL or less. I’ll need about 29-30 MOA to get from 100 yard to 1000 yards with a Berger 155gr VLD @ 2960fps. By contrast, in Raton, NM, located at 6600′ ASL, I’ll only need about 24-25 MOA to do the same. That’s a significant difference.

One thing to remember — it is the barometric pressure that really matters, not simply the nominal altitude. The barometric pressure will indicate the reduced pressure from a higher altitude, but it will also show you the pressure changes as a front moves in, etc. which can play havoc w/ your calculated come-ups. Most altimeters are simply barometers that read in feet instead of inches of mercury.”

Catshooter adds: “As Milanuk states, it is NOT altitude, but the LOCAL barometric pressure that is key. The two atmospheric conditions that effect bullet flight are air temperature, and barometric pressure – the humidity has so little effect that it need not be considered.

One important thing to remember is that the barometric pressure given on the radio station has been corrected for sea level. So in Denver (at 6,000 feet amsl), if the local pressure is 24″, the radio will report the barometric pressure to be 30″. If you do high altitude shooting at long range, bring along a Kestral, or remember to mentally correct the radio station’s pressure, by 1″ per 1,000 feet.

Offline rasbo

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Re: High Elevation Shooting
« Reply #3 on: May 29, 2010, 01:13:55 PM »
after you arrive to your destnation I would shoot my gun again before the hunt,lots can happen between home and there ;)

Offline MikeWalking

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Re: High Elevation Shooting
« Reply #4 on: May 29, 2010, 01:17:02 PM »
 :yeah: x2 always a good idea to check zero after the trip to camp.

Offline longrange7mm

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Re: High Elevation Shooting
« Reply #5 on: May 29, 2010, 01:28:23 PM »
zero your rifle at 6000' then you will be good at 4000' to 8000' when you get to your camp at 8000' you can re zero but it will be with in 1-2"  :twocents:
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Offline longrange7mm

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Re: High Elevation Shooting
« Reply #6 on: May 29, 2010, 02:18:37 PM »
We do the High Hunt here in the state and that is around 6000'.

I was just wondering if any gun guru's had any insight on if we should sight them in a little different here.
I shoot a 300 win.
He shoots a 7mm.

Thanks
cant shoot were you hunt i do every time i go out its the only place i found were i can shoot up to shoot 1000 yds out here
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Offline Bob33

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Re: High Elevation Shooting
« Reply #7 on: May 29, 2010, 03:20:52 PM »
My software indicates that a 180 grain bullet with a BC of .45 leaving the muzzle at 2960 ft/second, and sighted 3" high at 100 yards will be about 14.7 inches low at 400 yards when shot at sea level with a barometric pressure of 29.6 inches of mercury.  The same bullet shot at 6,000 feet elevation, assuming a standard drop in barometric pressure as elevation increases, would be approximately 12.9 inches low at 400 yards.

If you're shooting at 400 yards or less you have far more important factors to contend with.  If you're shooting at distances well in excess of 400 yards I could encourage you not to do so on live game until you understand the effects of barometric pressure on the trajectory of your loads, validated through extensive practice.
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Offline HoofsandWings

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Re: High Elevation Shooting
« Reply #8 on: May 29, 2010, 03:31:37 PM »
If you give me the bullet weight, ballistic coefficient, muzzle velocity and if your zero is at 100, 200 or 300, I can
give you expected trajectory at say 1000 feet elev and 8000 feet.
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Offline Bob33

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Re: High Elevation Shooting
« Reply #9 on: May 29, 2010, 05:33:53 PM »
It sounds like altitude will not be an issue for you.  As for "good" bullets, the most important element of "good" is accuracy.  Guns tend to be finicky about what they like.  Find something your gun likes, buy some extra boxes, and practice shooting from field positions.  (Make sure you save one round for the deer; that's all you'll need, right?)
That is the best approach you can take. 
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Offline carpsniperg2

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Re: High Elevation Shooting
« Reply #10 on: May 29, 2010, 06:14:07 PM »
alomst all my guns love the nosler partition, they are one of the best bullets that i have shot and tested over the years. you might check them out and see what you think.
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Offline WDFW-SUX

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Re: High Elevation Shooting
« Reply #11 on: May 29, 2010, 06:27:27 PM »
Nosler partition = meat grinder......thats not a bad thing :chuckle:
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Offline HoofsandWings

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Re: High Elevation Shooting
« Reply #12 on: May 29, 2010, 09:13:03 PM »
If you sight in at 200 yards, you should be good to go.
Find a range that has 300 yard targets. That will be the worst case senario.
You should be able to belly crawl to close the gap should the range be father.
Also, if you get fixated on deer at those ranges, you are not being very stealthy.
Don't stand on top of ridges and glass. Crawl.
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Offline haugenna

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Re: High Elevation Shooting
« Reply #13 on: May 30, 2010, 04:25:16 PM »
Your zero for 200' and 6000' is going to be the same.  You will notice a difference in flight around 500 yards.  Before the 500 yards it may be an inch or two off.

Offline Skinnyman

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Re: High Elevation Shooting
« Reply #14 on: May 31, 2010, 08:39:43 AM »
I have never hunted outside of WA, but I do know that elevation, pressure, and I have heard humidity can change things a lot. Not only that, who knows what happened to your rifle and rifle case in transit. Sight it in when you get there, better to be safe than sorry. Don't kick yourself because you miss a shot at a great animal. Charts are a great rule of thumb and starting point, but aren't always correct in real world (so many variables, gun barrel, rate of twist, humidity, bullet weight, powder type and charge, shooters capability, etc., etc.). Sighting it in gives me peace of mind and confidence in the field!! If you are spending the money and time to travel that far and buy non-res. tags, a few shots at a target are well worth it.

Also, try a barnes TSX bullet. Expensive!!! Your gun with either shoot them incredibly well (better than any others), or will spray them worse than your 12 gauge. I have found that there isn't much in between with them. You will know pretty quick if they work well or not. Your gun will either love them or hate them.

Offline boneaddict

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Re: High Elevation Shooting
« Reply #15 on: May 31, 2010, 09:23:07 AM »
To answer your question.  Aim and shoot, it isn't going to effect you in any "normal" sense.  I think this way with any of my rifles if its under 300 yards.  If you are a good shot, nothing else will matter enough.  If its beyond that, then experience needs to take over, and we can't give that to you. :)

Offline WDFW-SUX

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Re: High Elevation Shooting
« Reply #16 on: May 31, 2010, 09:28:00 AM »
Quote
Charts are a great rule of thumb and starting point, but aren't always correct in real world (so many variables, gun barrel, rate of twist, humidity, bullet weight, powder type and charge, shooters capability, etc., etc.). Sighting it in gives me peace of mind and confidence in the field!! If you are spending the money and time to travel that far and buy non-res. tags, a few shots at a target are well worth it.

Also, try a barnes TSX bullet. Expensive!!! Your gun with either shoot them incredibly well (better than any others), or will spray them worse than your 12 gauge. I have found that there isn't much in between with them. You will know pretty quick if they work well or not. Your gun will either love them or hate them.


 :yeah:
THE WASHINGTON DEPARTMENT OF FISH AND WILDLIFE SUCKS MORE THAN EVER..........

 


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