# Come ups and come downs

#### Boyd Heaton

##### Well-Known Member
You first have to tell us the Velocity,bullet weight,b.c. of the bullet and altitude you are at.And we can get you in the ballpark....

Im sorry about that i totally forgot. Im shooting a Sierra 168 gr. BTHP.

thanks

Howdy, I was wondering if someone could help me out a little. I have a rem model 700 sendero chambered in a 7mm Mag. I was wondering if someone could give me the data for comeups and comedowns for my scope. the ranges i need are 100 yds through 1000yards. And if you have the data for a 10mph wind to 30 mph ill be mighty obliged.

thanks

Wesley85

The info you're asking for is not available to us (in exact terms), you need at a minimun the velocity, bullet Ballistic Coefficient (BC), ambient temperature and elevation. With this info we can give you a computer approximation which you will need to verify at the actual ranges desired.

Here's a thread that covers this sort of thing.
http://www.longrangehunting.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=10&t=000004

If you don't have a chronograph you can still get come-up data from actual firing.

First zero the rifle to hit Point Of Aim (POA) equals Point Of Impact (POI) at 100 yards.

Now, (use these numbers as an initial go-by) adjust the scope UP 1 minute (4 "clicks on a 1/4 MOA scope). and shoot at the 200 yard target. Record the distance above or below the EXACT POA that the bullets (group) strike the target. Adjust the initial 1 minute elevation by 1/2 the error distance (if the bullet hits high then SUBTRACT 1/2 the error amount from the 1 minute and if the bullets hit low ADD 1/2 this value to the 1 minute).

Now that you have data for 200 yards, ADD 2 minutes of elevation ON TOP of the 200 yard adjustment. this should get you very close for 300 yards. Shoot a group and measure the error either high or low and divide by 3 for the necessary ADJUSTMENT to the current scope settings. If the scope is set on 3 minutes (inches) up and the bullets are hitting 1.5 inches high at 300 yards then take .5 minutes off the elevation setting.

For 400 yards ADD 2 minutes to the 300 yard data and repeat the verification process but divide by 4 for the correction value.

For 500 yards ADD 2 more minutes and verify and correct (divide by 5).

For 600 yards ADD another 2 minutes.

For 700 ADD another 3 minutes.

For 800 yards ADD 3 minutes.