Range Report Truing Data + Actual drop

[CleanMoostang]

Went shooting at the beginning of the week and noticed my Ballistic AE was off, extremely bad, but never really noticed how much, I dont shoot often. I only have 2 distances I shot on Monday so I might need more, but maybe someone could tell me what I am doing wrong, or if I need to change my BC or what. When I true it with the actual drops I am getting, its telling me my MV is 4270fps.
Its telling me 300yd is 1.6 clicks. Actual drop on target is .9
Its telling me 500yd is 4.1 clicks. Actual drop on target is 3.0


Here is my setup..

Ballistic Coefficient - 0.243
.308 Custom Projectile 175gr (SMK 175gr HPBT)
Bullet Diameter - 0.308
Bullet Weight - 175gr
Native Drag Model - G7

Muzzle Velocity - 2470
Chrono - 10ft
Use Drag Model - G7
Reloading Data -

Zero Range - 100y
Zero Height - 0
Zero Offset - 0
Sight Height - 1.5 (roughly)

Zero Atmostphere - DA 1600
Mach or Temp - 60ºF

Max Range - 1050
Min. Range - 0
Range Inc. - 10y
Vital Zone Radius - 5in
Elev. Units - .1mrad
Wind Units - .1mrad
Spin & Stab - Off
Coriolis Acc. - Off

 

[sjb269]

I believe the BC your using will require the projectile to have a minimum velocity to be valid. Are you sure of the distances your shooting? You might be inputing some data incorrectly into the program. I'd try to erase "clicks" from my vocabulary, it makes things more confusing than they have to be.

 

[HD1911]

Not to split hairs, but I'd say his speed is more like 2730 to 2750

 

[CleanMoostang]

I always double measure my distances, I have a Bushnell elite 1500 range finder that I use, after also walking the distance to set the steel up. I count each stride as almost a yard, and roughly they are always close to what the range finder says.


So with a BC of .505, Native Drag G1, and MV 2770, at 300y it shows 1.2mil and 500y is 3.0mil. Tomorrow or Saturday I will test 700 and 900 and hopefully I will find a happy median.

ETA: I know the MV will need to be adjusted, as I am right at 12mil when shoot 985y, I know I have tested at that range before.

I wouldnt doubt that my MV is pretty slow, the rifle is a SPS-Tactical with 1-12twist 20''

 

[oneshot.onehit]

Did you calibrate your scope turrets, also did you check to see if your 100 zero is accurate?

 

[CleanMoostang]

Yeah, Same hole every shot mostly, largest group was still .5moa from bipod, and I have done a ladder test several times and its accurate.

 

[melloyello]

What load? What scope? When you say .9 clicks do you actually mean .9mil?
You are using a 20" barreled Remington so I don't see it pumping out the velocity that applied ballistics is giving me when I plug the numbers in. Witht the numbers you gave for 300, 500 and 985 I plugged them in the ballistic calibration function and it gave me a whopping 2949fps. I ask about the load/ammo to see what it should be putting out. I ask about the scope because I want to know if it's a good one. Does it track well? Have you done a tracking test to make sure? And lastly have you done anything different to the rifle since you last checked zero? Did you check your zero on the day you saw the difference in your program and your actual adjustment.
Truthfully, I don't think your scope is tracking properly or your zero is off. It just doesn't add up for me.

 

[CleanMoostang]

Heres my layout:
Remington 700 SPS Tactical 20'' 1/12twist
HS Precision stock
Bushnell Elite Tactical 3-12x44mm (1/10th click milmil)

Remington Brass (new)
175gr SMK HPBT
44gr. Reloader 15
CCI Primer
2.836 oal

I can go tonight or tomorrow and do a ladder test and provide pictures of the results, like I said Im not the best shooter and dont do it much, so I do have a tendancy to pull once a while but here are my previous 100yd groups while testing zero. Orange dot target was day I was testing dope, I pulled 2 high, other 3 are center hole. I always shoot steel 10"x10", and below is the steel at 500yd I was shooting at. 3 was close, and the other 2 more than likely me as I was shooting off the top of my SUV due to weeds and highgrass.

 

[CleanMoostang]

So your talking about doing what John did on this episode of MCM.. Bushnell Elite Tactical 6-24x50mm Rifle Scope Review Part 1 - YouTube
No problem, I can do that also. Should I make several dots across the bottom to confirm that when I really go back to zero, its hitting zero also?

 

[melloyello]

Do just like he did. Put a very visible/easily engaged target at the bottom of the board. Shoot it to make sure you have a good zero. If you don't, go ahead and get it right. Then run your tracking test, return it to zero and shoot the same target again. If you don't want to shoot the same target just walk down and put another over the original.

 

[Graham]

What are you calling a 'click'?

Make sure you are properly zero'd at 100y. Use a chronograph to get your MV. Environmentals shouldn't matter to 500y. If you are off by that much either your chrono is wrong or your scope isn't tracking.

 

[CleanMoostang]

My 100yd zero was actually hitting .4mil high so first thing I done was rezero it. I couldnt really get a good adjustment for each one, just me though, but I was only off like a click or two for each dot. The closest ones for each was my 2nd shot after adjusting from my misses

 

[CleanMoostang]

Also, after watching Johns video I think another reason I had trouble was because after each dot I returned to zero and tried to measure instead of staying at each dot and measuring to the next one...

 

[CleanMoostang]

*****FINALLY GOT SOME NEW RANGE TIME IN*****



So this weekend I finally got some extra time to go back out and shoot. Hoping you guys can now help me true my data a little bit.

Ranges started at 700 and went to 1,000.

You will notice on 813 and 900 I was a little low, so its safe to say I need to come up another .1-.2 mils
And for 1,000 my setup runs out of elevation at exactly 10.7mil, so I was holding over for 11.7 and holding the top of the steel and still hitting low, so several more clicks was needed.

 

[CleanMoostang]

Edit:

I was putting the information in the Truing section incorrectly, I now have it figured out. Thank you.