I need help.(AGAIN)

[Boyd Heaton]

I am tring to get my click's on my scope right.They are 8th inch click's so they say.What I need to know is how to figure out how many click's for how many yard's.I have a drop chart in inches.This is what I have.A ave velocity of 3102 a bullet weight of 220gr.And a BC of .614.If my zero is at 500.And the drop to say 875 is 94.51 inches.How do I figure out the number of click's I need.What is the formula.I know this may sound like a dumb ? to you guy's.But I really am stumped.

 

[Dave King]

Boyd

Here's the secret:

Take the amount of drop at the desired range (94.51)

Divide by the desired range in hundreds of yards (875/100 becomes 8.75)

Answer is 94.51/8.75 = 10.80 of come-up over the Zero range.

Here's the stickler... the drop you stated is in inches, many scopes adjust in MOA. If your scope adjustments are MOA then you'll need to divide 10.80 by 1.047 to get MOA of adjustment. 10.80/1.047 = 10.32 MOA of come-up.

Peter Cronhelm posted a thread about the 'Thing', a ballistics spreadsheet. The thread is in Bullets, Barrels and Ballistics, it has a Ballistics page the shows this come-up value. The spreadsheet is free but requires Microsoft Excel to operate. It'll give you many of the answers you seek.

http://www.longrangehunting.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=3&t=000057

[ 07-30-2001: Message edited by: Dave King ]

 

[clif]

So Dave,
I am a little slow too. in your example, the MOA come-up is 10.32. So if there are 8 clicks per minute of angle, then that would be 82-83 clicks???
Also I down loaded your ballistics software and input this example. There is a comeup MOA column on the Ballistics Table. What is this number?
Question, it is hard to count out 82 clicks (for me at least) Would it work on your spread sheet to have an additional column to show how many full rotations of the elevation knob it would take to be 83 clicks?

 

[Darryl Cassel]

Cliff

To add some additional information here.

Not all scopes have the same full rotational values. Some have 60 Clicks per full turn while others such as Unertl have 50 clicks.

When you see a drop chart that has the amount of MOA at the various yardages just (in your case with a scope that has 1/8th min clicks) simply multiply the MOA times 8 to get your clicks needed at that range.
Your scope should also be marked with MOA lines so you can use it that way if you want.

You should always know your yardage and how much each click changes BULLET IMPACT at the various yardages.

Think of it as inches since the MOA is so close to that figure.
At 100 yards your 1/8 Min scope will change impact 1/8" or .125" --At 1000 yards(10X the yardage from 100 yds) the bullet impact change per click will be 1.250".

Hope that helped a bit.

Darryl Cassel

[ 08-07-2001: Message edited by: Darryl Cassel ]