Need help calculating "clicks" for elevation!

N

Northman999

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Fellows,

Okay, as there is no sticky in this I must me the only guy not able to figure this out...

I've got a couple of scopes with target turrets and I'm having a hard time proberly calculating how many clicks I need to turn my elevation knob in order to shoot right on at various ranges. For example, I put a white label on my elevation knob on my Zeiss Conquest 4.5-14x50 on my M14 and calculated ranges out to 500 yards in 50 yard increments, and marked my elevation knob accordingly...but when I got to the range, whatever I did was totally wrong as I was hitting way low (and lower and lower the farther away I got).

So, is there a "calculator" program out there, that can calculate the number of clicks a fellow needs to dial on his elevation turret, that can make things easy?

For example, here's my load and ballistics data that I want to translate into clicks for my turret:

Input Variables Firearm type Rifle Sight Height 3.0
Bullet Weight (grains) 165 Ballistic Coefficient .447
Muzzle Velocity (fps) 2750 Temperature 59
Barometric Pressure (hg) 29.53 Relative Humidity 78%
Zero Range (yards) 100 Wind Speed (mph) 0

Ballistics Table in Yards .308 win (M14) SST 165 gr., .447 B.C.
Range (yards) Muzzle 50 100 200 300 400 500
Velocity (fps) 2750 2649 2550 2358 2174 1999 1833
Energy (ft.-lb.) 2771 2570 2381 2037 1732 1464 1230
Trajectory (100 yd. zero) -3.0 -0.9 0.0 -2.3 -10.9 -26.9 -51.6
Come Up in MOA -3.0 1.7 0.0 1.1 3.5 6.4 9.9

What I get if I'm figuring this right is (1 click = 1/4" @ 100 yds)

Muzzle 50 100 200 300 400 500
Clicks -8 0 +5 +14 +27 +41

Am I doing this right? Like I said, last time I tried this my results were not useful at all.

If there's a calculator program or cheat sheet or something out there that would make this more foolproof, could someone point me in the right direction.

Thanks!
 
So, according to you, you are dropping 51.6 inches at 500 yards. So, let's just call it 51.5 inches. Now, if your scope is rated at 1/4"per click, 4 clicks should equal 1". Multiply 51.5 x4 and you get 206 clicks. One other thing, 1" and 1moa are a little off. 1moa = 1.047 ". So there is a little room for error. So, take your 51.6 and multiply by 1.047 and you get 54.0252 moa. Correct me if I'm wrong, but im pretty sure that's right. Looks to me like you just aren't dialing enough.
 
Try this ballistic calculator it might be of some help. www.biggameinfo.com/BalCalc.aspx

If i'm not mistaking once you enter your info and calculations are done it tells you how many clicks you need to make.

1 MOA = 1" at 100 yds, 1 MOA = 2" at 200 yds so on so forth. When calculating at different longer distance always return to your zero. Assuming your zero is 100yds.




JonnyBender
 
Your table suggests that you would be 9.9 minutes low at 500y.
Your scope has 1/4 minute clicks, so 9.9x4=40.6 clicks - 41 clicks.
Now, at 100y, a minute is just over an inch; at 500y, a minute is about 5.2 inches. 5.2x9.9=51.48 inches. Your table said 51.6 inches, we're pretty close.
You report that coming up 41 clicks isn't enough.
OK, it doesn't matter what the come-up is supposed to be, click on the elevation to get the rifle zeroed. Record that elevation.
I don't put marks on the knobs - I keep all my elevations on a sticker either on the scope, or on the rifle, plus in my notebook.
I have found that the elevations from the Sierra program that I use are generally pretty close. But nothing compares with actually shooting the rifle, and getting the actual settings.
And guess what? Once you have actual come-ups, obtained by shooting, they are going to be pretty close - but you will see slight changes from day to day, depending on the conditions.
 
knockturnal said:
41 clicks would only give you 10.25 " of up.
Click to expand...

10.25 MINUTES of 'up' x 500 yds of horizontal = 51.25" of 'up' at that distance.

Keep in mind that ballistic calculators are good - to a point. Have you chronographed your load? Have you taken into account barometric pressure and relative humidity? Are your bullets actually delivering their nominal BC? Have you used the correct drag model for the ballistic calculator - G1 vs. G5, etc.?

BC programs are meant to get you "in the wheelhouse" but there's no substitute for REAL shooting in REAL conditions. There's a reason that snipers keep a data book with every minute detail of the conditions in which they've shot.

If the BC program is giving you dodgy numbers, but you're still on paper, then just dial in your corrections and record them in your "as shot" chart which is the only one you should need for that load thereafter.

-M
 
Additionally, you may want to also verify that 1 click of your scope actually equals .25" of adjustment.

Sometimes, it is not always the case or not always the case through the range of the scope.
 
Range drop Clicks
0 -3.0 0
100 0.0 0
200 -2.4 5
300 -11.0 14
400 -27.0 26
500 -51.8 40
600 -87.0 55
700 -134.7 74
800 -197.3 94
900 -277.9 118
1000 -379.9 145
1100 -507.0 176
1200 -662.8 211
1300 -851.0 250
1400 -1074.8 293
1500 -1337.4 341
ww w.gunsim.com
 
Did you ran the load on a chrony?? My guest is that either your load isn't really at the indicated speed or your scope doesn't go up 10 in. at 100 when you dial 40 clicks
 
Fellows,

Yes, In chronied my load, and on more than one occaision. I think the first time I tried this I had different numbers and I also had my numbers (i think) based on my scope being 1.5" above bore, as that is what the ballistics software had as a standard. Later I got out my measuring tape and double checked, and it was actually 3.0" so I adjusted for that.

Thanks for all the help. You guys are a great source of knowledge, as usual. I'm hopeful I can take it from here and get good results!
 
Jeebus, 3" above bore?! To the centerline of the scope???

You must have the neck of a giraffe, and one hell of a large cheekpiece on that stock!

-M
 
Northman999 I find it easier to work in MOA not "clicks". It is very easy to loose track. Making your own scale for the turret and everything is just too hard to keep track of. I say ignore the inches drop in your program all together. Your scope turret is already nicely marked out in MOA. Zero it and you should be good to go. Use the turret just like a micrometer spindle. Then there is no more asking "how many clicks was that again?". I was like you trying to change MOA into clicks when i first started with longer range stuff. Once you learn to "talk" in MOA it is way easier.
 
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