I posted the below message on another site. I could just record the dope and use it, but I want to know why dope doesn't match predict results. The gun is shooting tight. 500 was dead on. 700 was dead center but 1Moa low. I added 1 MOA for 800 yards and 1100 yards and all was good. The 195s are spot on, so I guess the speed for Chorono is good.

Is anyone else shooting this bullet past 700 yards? Is the BC the problem? I'm adding spin drift and corilois as well


"I'm having to adjust the BC at longer ranges(700 to 1100 yards). I thought it was because I estimating speeds, but I now have a magneto sporter.

I'm running a 8tw Shilen barrel 26 in. Speed with h1000 is 3090 fps. 600 ft altitude. Anyone want to run these numbers and post predicted MOA for 7 to 1100 yards. 33.2 lat. 68.8 heading.

The 195s are tracking with the predicted results all the way to 1100 yards. "

Did you adjust for scope height?

I did. The bergers were 1/2 MOA high. I moved the height from 2 to 2.4 after I remeasured.

Adjust for temp? Temp drop would affect some at long ranges.

Could be just BC off.... what BC are you using? I assume G7.
A full MOA is quite a bit at 700 yards. Usually when it's that much off first I check my 100 yards zero and verify I am actually shooting a 100 yards.... one range I use the "100" yard range is 110 yards or 100 meters.

Don't sight in with Magneto but you already probably know that.

Also run dope on multiple ballistic calculators and see what difference you get.

While 1 MOA at 100 yards equals 1.047 inches, at 200 yards it equals 2.094 inches (2 x 1.047). To calculate MOA at any distance, multiply 1.047 by the distance in yards and divide by 100. On riflescopes with 1⁄4-MOA adjustments, each click equals .261 inch at 100 yards.

I'm going to go all in and say you are running a G1 BC. I'll bet you money you are running a G1. Why? A G1 BC is velocity dependent. As a bullet slows down, the BC decreases. When you run your trajectory data, you probably enter in the only G1 BC at a top velocity. So your trajectory program is calculating for only 1 BC, which is generally the highest BC number of that bullet at THAT higher speed. In reality, the G1 BC decreases as velocity drops, which your trajectory program is not accounting for. So, it plots a flatter trajectory than what you are seeing in the field. The correct answer- use a G7 BC!!!

Running a G1 BC is like driving a model T Ford. The G1 drag model is for a flat base soft point bullet shape. The G7 drag model is for a BTHP bullet, which most bullets are today. Use the G7 BC!!!

Bc discrepancies show up from 700 and out.

Hornady has velocity bands for their g7 bc on the new eld bullets. So you might check that to make sure.

I went through a bit of a bc truing on the 162 eld snd ended with a much lower bc than advertised.

What Chad and dee said.

Next time out, verify 100 yards, then step right out to 700 yards. And use a G-7.

Something else I've seen happen is a solid chrono speed input, but the DOPE says I'm slower. Chad's Labradar clocks my 6.5 Creedmoor at 2825 fps. In order to make my ballustic calculator trued I had to drop velocity in the calculator to 2790 fps MV.

After that it was reliable to 1350 yards.

I'm using StrelokPro. Using G7. Using multiple BC for
.401. 2513 fps
.392 2232
.381. 1953

500 yrds was spot on.

I check 100 yd zero before shooting always. I always check temp and pressure. On Sat 89, 29.42 at 575ft, 46% humidity.

Shot without the magneto and zeroed without it.


I'm going to load another 25 rounds. Shoot a couple to verify speed. Remove magneto and check zero. Then try again.


Again I got zero problems with the 195s after I corrected scope height.

Thanks for the help. I welcome all suggestions. This is really keeping me up at night.

Good information, thanks guys.

My specs are below if anyone wants to calculate my MOA for 800 and 1100 yrds
28 nosler
8 twist
3090 fps
2.4 in scope height
575 ft
29.42 pressure
89 temp
46% humidity
33.2 lat
68.8 azimuth
100 yard zero

About 30 fps slower makes the calculator close.

What discrepancies are there?

Calculator...vs...DOPE

For what it's worth just for grins I took my 284 Win shooting the 180 ELD-M at 2777fps and used Applied Ballistic app for data this afternoon. At 654 yards I shot 10 rounds 7 on steel and 3 on paper and all were low by 2.5 inches or about .1 Mil (1 click)

Not anywhere near a full 1MOA

I've always thought that the 180 ELD-M had an elevated BC. Why? The 195 Berger, which is heavier and sleeker shaped, shows a lower BC than the lighter 180 grain ELD-M, which appears to be about the same shape as the 195. So how does a lighter bullet have a higher BC with about the same shape? It doesn't add up. I have not shot the 180 ELD-M yet, so I have nothing to add, other than a tilted head and a squint in my eye.

I ran the 197grSierra yesterday in a a local match using the 28 Nosler and at 1000 the BC seemed legit on it.
Was perfect on 8 inch plates at 1000.

There a dozen or more different reasons why your calculated dope doesnt match actual bullet path. It could be anything from atmospherics to twist not being true since its a button barrel. I always tell people that ask balistic program get you close but you have to actually shoot to see what its going to do. Ive got rifles that shoot better than they should and ones that shoukd lower than they should using the same chrono and balistic program with b's i know to be true.