I got my Dope

[swampratt]

The math does not always compute so I set out yesterday to get the drop on my 30-06 and my .308.

I set zero at 100 yards and shot at 100-200-300-400 yards aiming at the same spot on the tall cardboard I set up to shoot at.

My chrony must be reading slow by over 100 fps for the math to work out when I compare it to a ballistic calculator.
This is why we need to actually shoot and see what happens.

.308 is a 168 gr. with a BC of .535
3" low @200 yards.
13.5" low @ 300 yards .
30" low @ 400 yards.

For 300 I set my scope turrets ar 4.5 clicks. At 400 I set it at 7.5 clicks.
The .308 is under 1.75" group at 300 yards.
At 400 yards it is under 3" group.


The 30-06 grouped well to 300 but barrel heat or maybe the load killed it for the 400 yard testing.
The online ballistic calculator to make the drop come out puts this 155gr at 3200fps or so..NO way i believe that.

30-06 load 155 gr Amax .475 BC
100 yard zero.
8.5" low @ 300 yards.
20-21" low@ 400 yards.
100 yard zero.

Going to clean the 30-06 barrel as i feel some copper fouling is creating some issues.

I found the scope clicks do not exactly match the inches of drop.. 1 click for 1"
Another reason to get out and shoot those guns.. get your own Dope

 

[Jcann]

I whole heartedly agree. Get out and run a tall target test to verify your scope is tracking correctly (it probably won't be). Adjust your ballistic app if it isn't. Then get out and shoot distance to verify what your scope and chronograph told you. My Magnetospeed does a very good job recording accurate FPS.

I posted a good article in general shooting on how to conduct a tall target test.

 

[swampratt]

I did my tall target test different.
My target was a 5 foot tall day glow orange cardboard with one aim point I made with electrical tape near the top..I made a cross with the tape.
Aimed at the center of the tape at each distance(100-200-300-400 yards) and sent 3 rounds at each distance.

Then I measured drop with a tape measure.. adjusted the scope for 300 yards and drove back to the 300 yard area and shot at a milk jug sitting on a 5 gallon bucket..exploded it but was a little high of centert..I needed to see something explode.

I then set up another milk jug and went to 400 yards and missed.. then aimed to the left ,,missed and then aimed to the right ,,missed again.
I then dialed less drop in the scope as the 300 was high so maybe the 400 is also.. So i took 1" out of it and this should be 4" less at 400 yards.
Center punched the milk jug of water.

When i inspected the jug for entry hole there were 2.. one was 4" higher almost to the top of the jug,, it passed through not hitting water as the jug was not clear full.

A better way would be to set up another tall cardboard and see if i can make the rounds land at the aim point at different distances.
I will probably do that on the next outing..
But i am still taking some jugs of water to explode.

Get this.. I measured out with a tape measure 300 feet (100 yards) of braided 60 pound fishing line..this stuff does not stretch like monofiliment.

I then put a loop at 100 yards..I have a big Penn fishing reel and there is 500 yards of this braid on it with a loop every 100 yards.

I ran this out to get my distances.
I will also run it out in my hunting area to get my distances.. and tie flags in the trees at each 100 yard interval..No more guessing how far.
I do not own a range finder.. This I feel is good for me.
Mark the area and reel the line back in.

 

[Shiredude]

3 things:
Buy a rangefinder, or borrow one. There is no sense getting dope out to 400 if you will never be able to tell how far something is before shooting at it.
Use the unit of measure on your scope turrets, whether MOA or MILs, don't use "clicks", inches, or anything else.
Check your scope height in your ballistics program. This is one of the most common mistakes that people make. I'm betting you used 1.5"? and yes, it absolutely matters. Get a good, 100% accurate measurement.

And what kind of Chrony? depending on sunlight, cloud cover, time of day, etc, some models can vary by much more than 100 fps.

And another thing, Adjust your ballistic app if you're scope isn't tracking correctly? what the heck for. Don't do this. Send that scope back and get one that works.
You may be speaking of a correction factor. Where as the scope tracks just fine but it is not 100% calibrated to the unit of measure. Meaning that up 10 MOA may only be 9.75". At which point you adjust by entering a correction factor. This has nothing to with a scope not tracking.

 

[swampratt]

3 range finders and 3 different measurements.. one did not want to measure at all after measuring only 2 times,, it failed. It was a Lecia.
My no stretch fishing line works perfect for me if i use it against my scope.Or a tape measure. No I did not use 1.5" scope height as mine is 1.675" on the .308 and 1.75" on the 30-06.
When i say clicks I am referring to 1" or really 4 clicks as my scopes are 1/4" per click @100 yards and my turrets are numbered and fall right on the money right on the clicks.
It returns to zero every time,, decent scope so if it is a bit off no issues really as it has been dropped, smashed, soaked and stomped many many times and never moves.

I have $166 tied up in this savage 10fp .308 and that includes the scope.. Did some trading..And I got the gun new from big boys.

Makes for a cheap hunting rig to test stuff out.

 

[Jcann]

And another thing, Adjust your ballistic app if you're scope isn't tracking correctly? what the heck for. Don't do this. Send that scope back and get one that works.
You may be speaking of a correction factor. Where as the scope tracks just fine but it is not 100% calibrated to the unit of measure. Meaning that up 10 MOA may only be 9.75". At which point you adjust by entering a correction factor. This has nothing to with a scope not tracking.

Sure you can send the scope off to be re-calibrated but there is nothing wrong with using a correction factor, it works. I know several shooters that use a correction factor.

We had a 7wsm GAP with a NF, 260 Savage with a Nikon, 308 Chandler with a Leupold, 308 Rem 5R with a Burris, and another GAP 338 Lapua with a S&B out one day shooting a tall target test. The only scope that displayed correct calibration was the S&B. That's not to say the other scopes are bad, we just used a correction factor and carried on. Or, like you said, we could send them back to the manufacturer and they will correct it (maybe) or they'll tell us there is nothing wrong with them.

Is our correction factor as accurate as a properly calibrated scope? No. But it does the job given all the other variables.

 

[swampratt]

Use a correction factor. Not something i have ever done. The only time i use a ballistic program is at home on the computer from a random sight like hornady.

Wouldn't it be just as good to just shoot at said target from different distances. Then adjust scope to same POI shoot again and find where the turret needs to be set for different distances for that load and wright it down on paper and remember it.

I know most people have a cell phone and an app for this but i do not have a cell or any electronic devices on myself.

I feel the cave man method i have should work..and did work.
Are you guys using the cell phone and apps etc.?

 

[jc5420]

Just shoot it and remember what you dialed, shooting to 400 yards and recording dope does not have to be very scientific. Hopefully you are using a powder that is not very sensitive to temperature fluctuations. A ballistics program is very accurate if the data given is accurate.

I record numbers from my chrony and run those with a tested and proven BC. This has always been spot on for me, especially within 400 yards.

 

[swampratt]

Yes I am using varget in the .308.
I have found IMR 4064 to be just as consistent and it is what usually works best in my 30-06.
Other powders that I use for those 2 guns are RL15 and 8208XBR..Believe it or not the H 4350 i have found not to be as consistent when temps change.
I first noticed it in my .243.. IMR 4064 was keeping groups tighter and less drop when temps got cold ..In fact my 95degree day groups looked good (clover leaf) with H 4350 and when the temps hit below freezing it was a scatter gun 2" groups.
The 4064 was .75" on hot or cold days.
Could be that my loads with the .243 do not fill the cases as full as the 30-06 or .308

 

[Shiredude]

yeah, sorry for any confusion. I am saying that the correction factor is definitely the way to go. What I meant was: there is a huge difference between a scope not tracking and one that is slightly off on come ups (calibration), don't confuse the 2.
If one is not tracking, send it back.