Forums
New posts
Search forums
What's new
Articles
Latest reviews
Author list
Classifieds
Log in
Register
What's new
Search
Search
Search titles and first posts only
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Hunting
Long Range Hunting & Shooting
Elevation and ballistics
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="700" data-source="post: 7544" data-attributes="member: 674"><p>Smoak</p><p></p><p>I have some altitude, temp charts, for the 175 Gr. Blackhills MatchKing at 2600fps. Perhaps I might join the fray.</p><p></p><p>Taking a standard sea level zero of Altitude 0 Ft. Temperature 59 F and Humidity 78% with sights on at 100 Yards. At sea level the bullet will be 5MOA low at 300 yards. </p><p></p><p>Without adjusting the scope turrets, the effect due to altitude at 7000ft will place the bullet 0.3MOA higher at 300yards than at sea level. </p><p></p><p>Now factor in the change in air density due to the approx 23 F drop in temperature between altitudes. Droping air temperature makes air more dense. Factor in additional drop of approx 0.06 MOA at 300 yards due to temperature.</p><p></p><p>To sum up</p><p></p><p>100 Yard drop at sea level = 0 MOA</p><p>300 Yard drop at sea level = -5 MOA</p><p>300 Yard press adjust. for 7000ft alt. = +0.3 MOA</p><p>300 Yard temp. adjust. for 7000ft alt. = -0.06 MOA</p><p></p><p>Summing the parts gives bullet placement at at 7000ft at 300 yards as approx 4.76 MOA below your sealevel zero. Thats 14 Inches. The bullet with plot 0.24 MOA higher than a 300 yard shot at sea level. Thats 0.72 Inches. Peanuts.</p><p></p><p>Lets look at whats happening at 100 Yards</p><p></p><p>100 Yard drop at sea level = 0 MOA</p><p>100 Yard press. adjust. for 7000ft alt. = +0.28MOA</p><p>100 Yard temp. adjust. for 7000ft alt. = -0.006 MOA</p><p></p><p>Summing the parts gives bullet placement at at 7000ft at 100 yards as approx 0.274 MOA above your sealevel zero. Thats quater of an inch.</p><p></p><p>All calculations are approx. Reductions in MV due to temperature have not been considered.</p><p></p><p>The important thing to remember is that the altitude change will make have no pratical affect on your sea level drop chart out to 300 Yards. Things go ballistic after 300 yards, and at 1000 yards, the Black Hills cartridge could be hitting 50 or more inchs above you sealevel tradjectory.</p><p></p><p>As you will be hunting at high altitude the possibility of an inclined shot is quite high. A 40 Degree inclination will put this load 9 inches high at 300 yards. Inclination is where you should concentrate your efforts.</p><p></p><p>Apologies for the long posting, especially as I am going over ground already covered by Len Backus,Brent and Jerry Teo.</p><p></p><p>Rgds</p><p></p><p>700</p></blockquote><p></p>
[QUOTE="700, post: 7544, member: 674"] Smoak I have some altitude, temp charts, for the 175 Gr. Blackhills MatchKing at 2600fps. Perhaps I might join the fray. Taking a standard sea level zero of Altitude 0 Ft. Temperature 59 F and Humidity 78% with sights on at 100 Yards. At sea level the bullet will be 5MOA low at 300 yards. Without adjusting the scope turrets, the effect due to altitude at 7000ft will place the bullet 0.3MOA higher at 300yards than at sea level. Now factor in the change in air density due to the approx 23 F drop in temperature between altitudes. Droping air temperature makes air more dense. Factor in additional drop of approx 0.06 MOA at 300 yards due to temperature. To sum up 100 Yard drop at sea level = 0 MOA 300 Yard drop at sea level = -5 MOA 300 Yard press adjust. for 7000ft alt. = +0.3 MOA 300 Yard temp. adjust. for 7000ft alt. = -0.06 MOA Summing the parts gives bullet placement at at 7000ft at 300 yards as approx 4.76 MOA below your sealevel zero. Thats 14 Inches. The bullet with plot 0.24 MOA higher than a 300 yard shot at sea level. Thats 0.72 Inches. Peanuts. Lets look at whats happening at 100 Yards 100 Yard drop at sea level = 0 MOA 100 Yard press. adjust. for 7000ft alt. = +0.28MOA 100 Yard temp. adjust. for 7000ft alt. = -0.006 MOA Summing the parts gives bullet placement at at 7000ft at 100 yards as approx 0.274 MOA above your sealevel zero. Thats quater of an inch. All calculations are approx. Reductions in MV due to temperature have not been considered. The important thing to remember is that the altitude change will make have no pratical affect on your sea level drop chart out to 300 Yards. Things go ballistic after 300 yards, and at 1000 yards, the Black Hills cartridge could be hitting 50 or more inchs above you sealevel tradjectory. As you will be hunting at high altitude the possibility of an inclined shot is quite high. A 40 Degree inclination will put this load 9 inches high at 300 yards. Inclination is where you should concentrate your efforts. Apologies for the long posting, especially as I am going over ground already covered by Len Backus,Brent and Jerry Teo. Rgds 700 [/QUOTE]
Insert quotes…
Verification
Post reply
Forums
Hunting
Long Range Hunting & Shooting
Elevation and ballistics
Top