Bullet dope card?
 

I typically just sight in 3" high at 100 yards and take it from there.

Say I want to zero at 100 and build a dope card; how do I figure out MOA?

Here is a online data list of my bullet choice. 257 weatherby mag. For example, how many MOA clicks to hit dead on at 400?

100 Grain TTSX muzzle vel = 3570fps
BC 0.357
100 yd 2.5
200 yd 3.2
300 yd 0.0
400 yd -7.9
500 yd -21.5

Thanks. I'm not thinking straight. This heat wave is killing me.

8 clicks at 400?

don't you first have to choose a zero?

i.e. 300yd zero and then you determine clicks to 400 based on that?

Get a ballistics calculator program and save the guesswork. You do have a chronograph don't you?

I run into this with my long range muzzle loader slug guns when shooting out to 600 or more yards. Here is what my mentor said to do and he has been the National black powder cartridge champion several times shooting out to 1000 yards.

- Gather all your ballistic information and go to a website such as JBM Ballistics at: JBM - Calculations - Trajectory then enter the info. Big items are bullet velocity and how efficient it is.

- Set where you want zero to be set at, in your case 100 yards. I use 50 to start with.

- Take the results and print it out and put in your dope book.

- Figure how scope #clicks affect impact at different distances and put in the dope book. For example my Unertl 20X scope with mounts 7.2 inches apart give 1/4 MOA per click. Since mine is in MOA the actual distance impact changes at different ranges is different. Modern scopes are waaaaaaay easier for adjustments.

I do. However, it isn't possible at my gun range. I bought an inexpensive unit that needs to be 12-15 feet down range of my rifle. Range HOT, no way I can get out there to adjust it so I can hit the berm safely without blasting the unit.

I need to find a private ranch to use mine. My buddy has the one you clamp directly on the barrel, but he's tough to pin down during the gun season.

Sucks. My home town, I just drive out to the wilderness. Here, cost me $15 to shoot shoulder to shoulder.

MOA = 1.047" @ 100 yards, 2.094" @ 200 yards, etc.

So, @ 400 yards, 1 MOA = 4.188"

7.9/4.188 = 1.89 MOA.

Wait, not sure if that's right...

aaaaand that's why I prefer mils to MOA. :D

Depends on what your turrets are (1/2 or 1/4 MOA clicks?)
So, assuming my maths were OK above, that 1.89 MOA would be between 7-8 clicks if they are 1/4 MOA turrets, or between 3-4 clicks if they are 1/2 MOA turrets.

That being said, I'd see if you can find an "advanced" ballistic calculator or two, to refine your initial dope a bit further, then range verify.
There are other things that come into play, like what type of Cd model used (G1 vs G7 etc.), scope height-over-bore, barrel twist/direction, zero offset, temp/humidity, etc., etc.

Vash,

I suggest you stop by either the Snipers hide or 6.5 Grendel sites. Good technical help at both sites with little of the PARF flavor. I suspect both sites have better ballistic calculators than the one you are currently using.

Few scopes less than four figures actually match the listed click value. Need to check it first “dry” (w/o shooting), then while shooting groups in a box test. The former is relatively quick and easy but it will probably take a while with a .257 Weatherby letting the barrel cool between groups.

Most programs also specify scope height above bore, if you have an angled base and a bunch of other stuff to include atmospherics, altitude, location and direction of shot.

If your scope doesn’t track and you are going to replace I highly suggest you get one with both windage and elevation in the reticle and don’t mix units from reticle to adjustment; there are scopes that reticles in mils but adjust MOA or fractions of an inch/100 yards or meters. It’s much easier to use mil/mil or MOA/MOA.

My last suggestion is practice wind reading as that’s much more difficult than range/drop.

S/F, FOG

The ballistics calculator website I listed will take the info you have plus humidity, temperature, height above sea level (our range is 1255 FT for example) and such. It also figures that you are reading the velocity 15 or 20 or ??? feet from the muzzle so you do not have to move your chronograph.

Just played around with Hornady's basic one, using your values:
https://www.hornady.com/team-hornady/ballistic-calculators/#!/standard

But with a few additions:

Cd profile: G7
Height over bore: 1.5"
Altitude: 1000ft MSL
Barometric Pressure: 29.53
Temp: 55F
Humidity: 75%

http://forums.pelicanparts.com/uploa...1504501640.jpg


Quick-reference:

http://forums.pelicanparts.com/uploa...1504501658.jpg

Thanks! I'm ordering some new hunting rounds. Non-toxic rounds for my home state. I'm gonna get bent over paying the weatherby tax.

most ballistics calculators are decent enough, I use Sierra Infinity out to 1500 yds in Norway and was bang on target with a new rifle. The real issue is getting good BC numbers , get the Lutz G7 numbers and put that in your calculator.

Ballistic Coefficient Tables

But at 400 who cares really, it's a flat shooting bullet, the drop is peanuts..that's almost point blank range really..
Wind reading will be more important with such light bullets.
Diff between various calculators is next to nothing, splitting hairs at 400 yds

Anyway, try reading wind in a Norwegian Fjord with nothing but rocks and turbulence..