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7mm Elevation Tables
Posted: Sun Mar 10, 2013 9:26 am
by Hodgie
Is there somewhere to go to look up Elevation rises both in Metres and Yards using 7 mm with 180g Bergers with 51g of 09 ? . I'm a new shooter about to be sent to the unknown
Posted: Sun Mar 10, 2013 9:54 am
by bruce moulds
try jbm ballistics.
they have one section for range cards.
you will need to know the muzzle vel and the bc of the bullet.
about 2800 would be a guess for a 30" barrel.
the berger site also has a little programme.
keep safe,
bruce.
Posted: Sun Mar 10, 2013 7:41 pm
by RDavies
JBM now has a bullet library at the top of the trajectory page which you click on, scroll down to your bullet and it will automaticaly use the measured BC of the bullet you want to check.
Posted: Mon Mar 11, 2013 1:31 pm
by Hodgie
Thanks for the info, Have i done this right? Had enough of 4 sighters!.
.284 Win. 30inch 1 in 9 twist 180g Berger vld. 2820 mv, 51g 2209.
Assume 300y is Zero MOA
400y =+2
500y=+2.5
600y=+3.1
700y=+3.7
800y=+4.4
900y=+5.1
Posted: Mon Mar 11, 2013 6:07 pm
by mike H
The simple and best way is get the rifle zeroed at short range and go out and shoot,preferably working up a 100 yards/metres at a time. If you have any F/open shooters in your club,they should be able to help.
Mike.
Posted: Mon Mar 11, 2013 7:32 pm
by AlanF
Hodgie wrote:Thanks for the info, Have i done this right? Had enough of 4 sighters!.
.284 Win. 30inch 1 in 9 twist 180g Berger vld. 2820 mv, 51g 2209.
Assume 300y is Zero MOA
400y =+2
500y=+2.5
600y=+3.1
700y=+3.7
800y=+4.4
900y=+5.1
Hodgie,
Here's what I get.
400y =+2.5(MOA)
500y=+2.8
600y=+3.0
700y=+3.3
800y=+3.5
900y=+3.8
These figures use your given 2820fps, and a G7 BC of 0.337. Results will vary depending on temperature, air pressure, wind direction etc.
But do at least some of what Mike says to get a sanity check on the maths.
Alan
Posted: Mon Mar 11, 2013 7:58 pm
by macguru
Chris, here is what I get for the 180gr vld at 2850 fps
300m zero +3=
400m 3 +3=
500m 6 +3.5=
600m 9.5 +3.5=
700m 13 +4=
800m 17
my guess is that real world clicks at (say) lyndhurst would be a shade less than these, and the hybrids would do a bit better so you may take off 1/4 moa, say..
In yards , remember the rifle is still zeroed at 330 yds=300m. I think you forgot that, chris, so your starting point for saturday would be 14.5moa at 800yds, not 15.5, but i dont think either of us is far off...
330y zero +1.5=
400y 1.5 +3=
500y 4.5 +3=
600y 7.5 +3.5=
700y 11 +3.5=
800y 14.5 +3.5=
900y 18