Hunting Washington Forum

Big Game Hunting => Backcountry Hunting => Topic started by: jayrod9528 on June 30, 2013, 06:17:03 PM

Title: High hunt shooting?
Post by: jayrod9528 on June 30, 2013, 06:17:03 PM: So this may be a dumb question but, if my rifle is set at 1.5 inches high a 100 yards and my sight in elevation is 1000 ft what is my bullet going to do at 5000-7000ft in the wilderness?
FYI
.270 wsm
130grn nossler ballistic tip
3280fps
Title: Re: High hunt shooting?
Post by: jason stevens on June 30, 2013, 06:25:02 PM: At 300 and under I wouldnt worry about it but any further its gonna drop faster
Title: Re: High hunt shooting?
Post by: snowpack on June 30, 2013, 06:32:16 PM: drops less. The air is thinner, less drag. I think going from sea level to 1 mile gets you an extra 10% range.
Title: Re: High hunt shooting?
Post by: jayrod9528 on June 30, 2013, 06:43:03 PM: Two opposite answers? I tend to thing that it would give you more range?
Title: Re: High hunt shooting?
Post by: JLS on June 30, 2013, 06:54:47 PM: As you go higher in elevation, the air becomes less dense and therefore exerts less drag on the bullet. The forces of gravity are the same, but your bullet will not shed velocity as fast so drop is slightly less. I doubt the elevation difference you are talking is going to be a significant factor at normal hunting ranges. If you're into the long range stuff you would want to factor it in.
Title: High hunt shooting?
Post by: grizzlyadams on July 09, 2013, 06:51:09 PM: Download a ballistics calculator app for your phone. It will have elevation, temperature, wind. ballistics coefficient ect you can set for the round you are shooting. Then you will know what your bullet is doing at any given range. If you are shooting longer ranges, don't forget the angle cosign. More misses can be contributed to the angle you're shooting than anything I believe. If you're shooting 250 yards or less not much to worry about.
Title: Re: High hunt shooting?
Post by: MichaelJ on July 09, 2013, 07:01:06 PM: Your hundred yard zero won't change. Depending on caliber you'll be within 1-2" out to around 600 yards. After that conditions really start playing havoc with trajectory.

Mike
Sent from my C771 using Tapatalk 2
Title: Re: High hunt shooting?
Post by: Wazukie on July 09, 2013, 07:03:17 PM: At 1000' above sea level

Range (yrds) Drop(in.)

100 1.5
200 .8
300 -4.2
400 -14.4
500 -30.5

At 6000' above sea level

Range (yrds) Drop (in.)
100 1.5
200 .8
300 -4.0
400 -13.5
500 -28.4

This is all based on your numbers and bullet and calc's from http://www.jbmballistics.com/index.shtml (http://www.jbmballistics.com/index.shtml)
Title: High hunt shooting?
Post by: grizzlyadams on July 09, 2013, 07:19:19 PM: Quote from: MichaelJ on July 09, 2013, 07:01:06 PM
Your hundred yard zero won't change. Depending on caliber you'll be within 1-2" out to around 600 yards. After that conditions really start playing havoc with trajectory.

Mike
Sent from my C771 using Tapatalk 2

Huh? 1-2" off at 600 yards. You must be shooting a Star Wars laser rifle or something. I want that rifle and so will the military.

Maybe it's one of those new upward traveling bullets. You know... The ones that arch up 2 feet before they begin to drop. Chuckle. ;-)
Title: Re: High hunt shooting?
Post by: deerslyr on July 09, 2013, 07:26:56 PM: Quote from: grizzlyadams on July 09, 2013, 07:19:19 PM
Quote from: MichaelJ on July 09, 2013, 07:01:06 PM
Your hundred yard zero won't change. Depending on caliber you'll be within 1-2" out to around 600 yards. After that conditions really start playing havoc with trajectory.

Mike
Sent from my C771 using Tapatalk 2

Huh? 1-2" off at 600 yards. You must be shooting a Star Wars laser rifle or something. I want that rifle and so will the military.

Maybe it's one of those new upward traveling bullets. You know... The ones that arch up 2 feet before they begin to drop. Chuckle. ;-)

He means your drops will be 1-2 inches off out to 600 yards, meaning it will have little affect if you know your drops.
Title: High hunt shooting?
Post by: jackelope on July 09, 2013, 07:27:13 PM: I think what Mike is saying is there will be 1-2" difference in where it normally shoots at those extended ranges.
Title: Re: High hunt shooting?
Post by: MichaelJ on July 09, 2013, 07:29:32 PM: Quote from: grizzlyadams on July 09, 2013, 07:19:19 PM
Quote from: MichaelJ on July 09, 2013, 07:01:06 PM
Your hundred yard zero won't change. Depending on caliber you'll be within 1-2" out to around 600 yards. After that conditions really start playing havoc with trajectory.

Mike
Sent from my C771 using Tapatalk 2

Huh? 1-2" off at 600 yards. You must be shooting a Star Wars laser rifle or something. I want that rifle and so will the military.

Two examples, and I'll even give you the data so you can run them through a quality ballistics program.
They say about 1" pressure difference is about the same as 1,000' in elevation change so we'll use 29" and 24" station pressure.

First up: 300 Norma Mag. 215 Grain berger at 3165, G7 BC of .356. 100 yard zero
At 29" Station pressure, 80* F, 50% humidity: Drop at 600 yards = 56.53" drop
At 24" station pressure, all other factors equal drop at 600 yards = 54.2"

Change it up to 700 yards.
29" pressure, Drop at 600 yards = 83.58"
24" pressure, Drop at 600 yards = 79.63"

Next up is my 280 ackley.
168 grain bergers at 2950 fps, G7 BC of .316, 100 yard zero.
29" station pressure, 80*F, 50% humidity: Drop at 600 yards = 67.21"
24" station pressure, 80* F, 50% humidity: Drop at 600 yards = 63.91

Change it up to 700 yards.
29" pressure, Drop at 600 yards = 100.22"
24" pressure, Drop at 600 yards = 94.49"

Once you get past 600 yards is where you really need to start paying attention to environmental conditions...

Lets hope that clears up any misunderstandings we're having around here...

Mike
Title: Re: High hunt shooting?
Post by: Bob33 on July 09, 2013, 07:43:12 PM: The simple answer is that it does not make any significant difference at any distance you should be shooting. Anyone planning to accurately shoot at extreme distances where this might matter would know the difference. :twocents:
Title: Re: High hunt shooting?
Post by: Wazukie on July 09, 2013, 07:50:37 PM: :yeah: best answer yet :tup:
Title: Re: High hunt shooting?
Post by: haugenna on July 09, 2013, 08:13:36 PM: Quote from: MichaelJ on July 09, 2013, 07:01:06 PM
Your hundred yard zero won't change. Depending on caliber you'll be within 1-2" out to around 600 yards. After that conditions really start playing havoc with trajectory.

Mike
Sent from my C771 using Tapatalk 2

:yeah:
Title: Re: High hunt shooting?
Post by: Skillet on July 09, 2013, 08:36:24 PM: I have the same caliber but shoot 140 accubonds. If you're truly hunting at 5000-7000 feet, you will need to worry far more about how the steep angle of your shots reduces your drop than atmospheric density. Not many flat 100 yard ranges up there...
Title: High hunt shooting?
Post by: grizzlyadams on July 11, 2013, 12:04:50 PM: Ok sorry about that. I misunderstood what he was saying. Sounded like he was telling the OP that there would only be a 1-2" drop In his round out to 600 yards.
Title: Re: High hunt shooting?
Post by: HawkCreek on July 11, 2013, 07:14:19 PM: The Hill People Gear rifle card is handy for this type of thing. While not meant for precision work it is quite suited for hunting scenarios.