I cannot remember where but some time back ('10 or even earlier) I read an article somewhere about setting your scope for a specific rante - 200 yds IMS - and then aiming high or low for longer or shorter ranges.

Would someone point me to a good primer on the subject? I remember the general idea but none of the specifics stuck.

How do I determine how much to adjust my aim point? Determining range to target is no problem - I get that from the parallax adjustment range on my SS scope. My question regards knowing HOW MUCH to adjust the aim point.

I will know muzzle velocity because I will be using a chrony when I develop my loads. How can I know how much velocity the projectile will lose in flight? Is there a way to calculate it?

Alternatively, is bullet drop over range something that can really only be determined empirically?

You folks are the experts so I will accept your pronouncements.

I have been working on the same thing. My 6 x 284 is zeroed at 400 yds and I hold under for shorter and over for longer shots. I use a mil dot scope and there are many good articles on how to use that type of scope. Having a known distance is a big plus when using hold over.

You will need to develop a drop chart for the round you will be shooting. You can do that with a computer program or the most accurate way would be to fire the rifle at say every 100 yds. out to as far as you want to shoot. You would measure the drop at each distance and thats how much you need to hold over. I like this system but many others hate it with a passion. Dialing up your elevation seems to be the most accurate way of hitting where you want at long distance. I just think it is slower and your scope needs to be high quality to insure it returns to zero each time you dial it back down.

Plenty of ballistic programs around that you feed the BC and MV of the bullet you are using, the distance you have it sighted in and it tells you the + or - inches at the other ranges. You would then have to verify the information by actually shooting at some of those ranges. BTW I would not count on your scope's parallax adjustment giving you an accurate range. Again, verify by testing. The problem is estimating the holdover ie. say you have to hold up 5 inches at 500 yards. How do you estimate 5" at 500 yards? Better off with a mil dot scope, or a Zeiss Z-reticule scope, or something similar. Don't expect high precision!
Peter.

Here's a good on line ballistics calculator.
I like the price.
FREE:

Have fun:

http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

Thanks for the sage advise all.

quote:

Peter advised:

BTW I would not count on your scope's parallax adjustment giving you an accurate range. Again, verify by testing.

Peter,
Fortunately I have already confirmed that the markings on the scope are essentially correct. The range I shoot at - A Place To Shoot (catchy name, isn't it?) has ranges out to 300 yards. I checked it and as long as I have the primary focus right, the parallax is VERY close from 25 to 300 yards.

get you a quality range finder and a balistic program....I use "bullet drop" on my iPhone

You need 5 things to get good results with this "gadget"

Correct MV
BC of your bullet
grain wt of said bullet
zero range distance
wind speed and direction

after you enter the data the program will tell you the hold over and hold into