6.5 SAUM Drop and data questions

[Akhunter907]

Well, figured I'd poll the fellas. Having issues with shooter drop data past 500 or so.

Specs on rifle: 24 inch gap Barreled stiller. Ammo: 130 berger vld hunters, cci mag primer and H1000 at 63.0 muzzle velocity is right around 3200. Using a 100 yard zero

Data to 500 seems to be spot on. My actual drops past that are more than shooter is telling me. I'm using Litz data for the 130. We are confirming atmosphere with 2 different kestrels.

Here is first example, not boring you with atmospheres. 678 yards. Shooter called 11.1 moa. Needed to adjust to 11.5 to correct

865 yards. Shooter wanted 16.3 moa. Actual needed was 17 moa

1150 yards shooter wanted 24.2 moa. Actual needed was 26.5

So of course my actual data will be the driver for range cards but would love to correct shooter to be more accurate. I entered the multiple Litz BC's for velocity. I'm going to verify all my zero info. Zero is at sea level with shooting at 4000 or so. But I am correcting for baro. My first guess is my BC is just not holding up at extended ranges,,,,,,

Thoughts??

 

[PS-G1_Sniper]

Maybe a G1 vs G7 issue?

 

[Akhunter907]

I'm using G7 data. I just got done putting in both velocity changes and bc changes. It took a ton to get things to align. I'll recheck a zero this week too. For what it's worth. First outing with a 250 zero had me pretty close. Or closer. Buddy has a different crony to try too. I'm trying to figure out user error, so far haven't found anything. But I'm off somewhere

 

[ballistic1]

I would enter your actual verified dope that you have witnessed at 678, 865, & 1150, in
the Velocity calibration menu and hit calculate, then apply. Exiting back out of that menu, hit
your results arrow to produce a "trued" drop chart.
Every time I have set up a new load, and done the above, my dope charts have
been spot on.

With that being said:
I shoot the same land often. I set up my shooting position in the same place,
and we shoot to the same distant targets, due to the lay of the land.
Using the same rifle, my Surgeon 308, shooting Fgmm 175,
at 945yards, my Shooter app has produced drop charts that vary
from 31.75 Moa to 35.5 Moa. This is from winter to summer times, in
all different temps and enviroments, but always the same place.
I shoot in Wisconsin at 1100'

For example, I can shoot day 1, and pull a dope of 31.75.
The next day, shooter will show me 32.5. The next day, mind you..
Sure as hell, you dial it in, and ding, center mass. The dope has changed
just like it states, with the environmentals.

Anyway, my point is, use the velocity calibration menu on the shooter app.
This will bring your particular load you shoot into calibration.
Then use the app to produce a fresh chart each time you shoot, because
your dope will inevitably change as DA/ humidity/temps, etc fluctuate.

I have found that out to 500yds or so, my dope is pretty constant, never
really varying.. not enough to notice.
But at 945yds, it can be quite different and very noticeable.

So each time we go out, I wait for shooter to pull down the station pressure
and environmentals, and hit results to post a new chart. Even though the day
or week before, I was clanking steel at one recorded dope, the current day
can be off enough to miss completely.


On the velocity calibration portion, I have taken a load, shot it to 500, used that
dope to calibrate.. just that one entry, and had shooter produce a chart that
got me on target at longer ranges. I then take the newfound longer range
verified dope, and go back to the calibration menu, and enter that new info
as well.. doing it in steps like that saves money, time, and pills.
Generally speaking, after just a couple longer range calibrations per load,
I have found that my dope charts were spot on with no need for further
entry of calibrates.

Hope this helps you enjoy your shooter app more fully, cause it is very
capable of delivering correct, spot on dope, if you give it live verified calibrates
to adjust and true itself.

Happy shooting..

 

[Fongman]

Just a thought, but you may wanna shoot a box test to confirm your scope is tracking properly - especially if the ballistic programs never seem to line up.

 

[Akhunter907]

Well, as always should have started with the instructions. There is just a wealth of info on the shooters webpage. Many links to other great articles as well.

I was able to populate or correct the drops using the velocity correction. It does give proper drops, but it appears to only change velocity, and not the BC, and not that I care, but will just look at 500 and in to insure those still track. But here is the items now on my list to check and confirm.

1) Scope tracking, I'll make sure my scope is adjusting for true moa, its a march scope so I'm certainly hoping it will be, but after looking at speeds and everything else, it kind of makes some sense that this might be suspect......Frogman, will also do a box test too,,,,this seems like my biggest variable here. The differences just seem too great to be slightly off bc's or MV. My atmospheres were always checks against 2 different kestrels and my watch, which gives me just pressure.
2) Velocity, my velocities came off a magneto speed. I have a buddy with a Oehler 35 I'll shoot over this Wednesday to check speeds. My muzzle velocity was "corrected" to 3135 for the shooter program to correct for confirmed drops. My zero MV was 3196 avg

One thing I am doing, basically at the recommendation of a fellow shooter, is I'm entering that pressure is absolute. And then entering the current baro. And this makes perfect sense to me, the bullet does not care what the altitude is, but it does care what the pressure is. It also simplifies things since I do not have the two variables to enter as well. Makes sense to me, but wanted to get thoughts here.

Basically all my "zero" shooting is at or near sea level, all my hunting and shooting will almost always will be above 2000 ft, and in the case of a upcoming hunt, most likely above 5k, so getting alignment is pretty critical to me. I have another place I can get to 4500ft, its a bit more work to get into, but I can get additional data this coming weekend. As close as I can get to actual, upcoming conditions.

 

[105amatt]

Believe the bullet.

 

[Akhunter907]

Well, hate the posts that never get resolved, so anyway, I found my problem.

My scope is not making full MOA adjustments. It was pouring at the range, so will reconfirm, but with a 36 moa adjustment, scope moved 36 inches and not the 37.5 inches it should have. velocity was confirmed with a second crony, no issues there

With some math, this gave me a scope adjustment factor of 1.045 Once I did this I went back and re-entered about 15 different range setups, with conditions and crunched the numbers. They were all spot on, with about maybe a .25 moa shift, but that could have been simply spotting a hit on a plate slightly higher or lower than actual.....

Anyway, I'm happy The adjustment is made under the rifle section, so as long as that scope sits on that rifle I'll be good. Will be going out next weekend for more confirmation, but should be good to go

 

[Fongman]

Well, hate the posts that never get resolved, so anyway, I found my problem.

My scope is not making full MOA adjustments. It was pouring at the range, so will reconfirm, but with a 36 moa adjustment, scope moved 36 inches and not the 37.5 inches it should have. velocity was confirmed with a second crony, no issues there

With some math, this gave me a scope adjustment factor of 1.045 Once I did this I went back and re-entered about 15 different range setups, with conditions and crunched the numbers. They were all spot on, with about maybe a .25 moa shift, but that could have been simply spotting a hit on a plate slightly higher or lower than actual.....

Anyway, I'm happy The adjustment is made under the rifle section, so as long as that scope sits on that rifle I'll be good. Will be going out next weekend for more confirmation, but should be good to go

Scope may be operating just as it was designed to. It probably has been set up to deliver "Shooter MOA" adjustments. Which is equal to 1" at 100 yards and not the 1.047

One of the problems of using MOA adjustments is the lack of knowledge of what the manufactures may have used in their set-up. Now that you know for sure as long as it's repeatable you're good to go.

 

[Akhunter907]

I repeated the scope test. Repeated my velocities. All good to go. My March is adjusting in true moa

I last piece is BC. Are folks finding the 130 bergers accurate at .282 G7??? Did another trip out today. Farthest was 920 or so. If I adjust the BC to .274 then I start aligning shooter with field drops

So are folks seeing any mods needed to the 130 berger?? 282 has proven too high for me. Was wondering if others had this issue. Thanks