Range Report Sterlok+ vs JBM Elavation Solution is off up to 1 MOA at 1000yrds

[Beiruty]

I just wanted to compare Sterlok+ vs JBM
Here is the input:
Manufacturer: Hornady Description: A-Max®
Caliber: 0.308 in Weight: 208.0 gr
Ballistic Coefficient: 0.648 G1 (ASM)
Muzzle Velocity: 2950.0 ft/s Distance to Chronograph: 0.0 ft
Sight Height: 1.40 in Sight Offset: 0.00 in
Zero Height: 0.00 in Zero Offset: 0.00 in
Windage: 0.000 MOA Elevation: 0.000 MOA
Line Of Sight Angle: 0.0 deg Cant Angle: 0.0 deg
Wind Speed: 5.0 mph Wind Angle: 90.0 deg
Target Speed: 0.0 mph Target Angle: 90.0 deg
Target Height: 12.0 in
Temperature: 57.0 °F Pressure: 29.50 in Hg
Humidity: 0 % Altitude: 603.0 ft
Vital Zone Radius: 5.0 in
Std. Atmosphere at Altitude: No Pressure is Corrected: No
Zero at Max. Point Blank Range: No Target Relative Drops: Yes
Mark Sound Barrier Crossing: No Include Extra Rows: No
Column 1 Units: 1.00 in Column 2 Units: 1.00 MOA
Round Output to Whole Numbers: No

JDM Solution:
Range Drop Drop Windage Windage Velocity Mach Energy Time
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s)
1000 -264.2 -25.2 30.2 2.9 1658.0 1.488 1269.5 1.360

Sterlok+ solution:
Range Drop Drop Windage Windage Velocity Mach Energy Time
(yd) (in) (MOA) (in) (MOA) (ft/s) (none) (ft•lbs) (s)
1000 -252.48 -24.11 28.27 2.7 1716.9 ? 1261.3 1.340


Now what should solution should I trust? 12" at 1000 is too much, no?

 

[bogeybrown]

I didn't go through all your inputs line by line, but big picture:

12" at 1000yds is roughly one full MOA, not .5MOA as the thread title indicates

Keep in mind that every single ballistics solver is a best-guess approximation based on it's own algorithms. I would guess that if you plugged your information into Atrag and Applied Ballistics you'd get 2 more (different) answers. NO solver is going to be dead-nuts accurate for your particular rifle all the time. This is where truing comes in:

Pick the solver that has the friendliest interface for you, and has the features you want, whether that's the ability to work with a G1 or G7 BC, or known offset when using a suppressor, or whatever. But pick one for now. True that solver per their recommended method and your observed impacts. You'll need some fairly long ranges to do this properly and to true your MV and BC.

Once you've trued your program, run a course of fire with it and see where you are in terms of projections and actual impacts. YES, 1 MOA is a decent variation at 1000yds, but keep in mind that holding to 1 MOA of accuracy at 1000yds is an optimistic goal for a lot of us.

There is such a thing as information overload. At a certain point you're faced with so much of it, you either can't process it all or you don't know which to trust. Run ONE for now and see where you are. If you feel like that one isn't giving you the information you want, then switch. I like JBM to run a rough range card before I leave the house, but what's happening inside my AB Kestrel is what I make my decisions off of.

 

[xdeano]

The computer has and never will be hard data. Take your computer drop chart and actually shoot it, this should get you started at extended distance. Then write it down, this is your true drop.

xdeano

 

[Graham]

Sterlok+ vs JBM Elavation Solution is off up to 1 MOA at 1000yrds

Check your inputs. I have not yet, in two years of use and with three new calibers, ever had to modify my Strelok computer data at under 1000 yards.

 

[Drifter™]

Link: Ballistic Program Inaccuracies

 

[XTR]

Reality and G1 BCs are not necessarily the same

Reality and Hornady BCs - see above

If you have the choice and you have access to one of Brian Litz BCs for various bullets then use them. You will get better answers.

Go shoot, get the answer.

Lastly, with my F-TR rifles my cold bore (not necessarily cold, clean bore) shots are typically 1MOA low. on the first sighter of the first match, and if I have to go to the pits for three matches and come back it will be closer to ½ to 3/4 low.

No program can substitute for DOPE.

 

[bogeybrown]

As a follow up, as several guys have correctly mentioned in one form or another, ANY program is only as good as your inputs. An accurate MV and an accurate G7/Litz BC will go a long way to getting you there.

There seems to be 2 approaches to ballistic solvers: enter approximations into the system and true from there, or enter the absolute most accurate information available to start with and make minor adjustments if necessary. In either case, the solver is a time/money saver, but only shooting that data and noting your results is going to complete the picture for you.
[MENTION=13650]Graham[/MENTION], that's good to hear about iStrelok. I downloaded it a while back to play with because the interface is much easier than the AB Kestrel, but I wasn't really counting on it for the most accurate results. I'll have to play with it more when I'm home.

 

[CoryT]

Reality and G1 BCs are not necessarily the same

Reality and Hornady BCs - see above

If you have the choice and you have access to one of Brian Litz BCs for various bullets then use them. You will get better answers.

Go shoot, get the answer.

Lastly, with my F-TR rifles my cold bore (not necessarily cold, clean bore) shots are typically 1MOA low. on the first sighter of the first match, and if I have to go to the pits for three matches and come back it will be closer to ½ to 3/4 low.

No program can substitute for DOPE.

While advertised BC's may not be perfectly accurate, I would not go as far as to say they do not represent reality, just that they are not going to represent a perfect value for YOUR rifle/load. You are not going to see any improvement in reported solutions by using a G7 vs a G1 at ranges under 1K unless the solver is junk anyway. There is a string possibility that there is some small mismatch in data entry responsible for the difference shown.

I take strong exception to the statement that no program is a substitute for DOPE. Quite the contrary, good programs completely replace traditional DOPE/log book solutions and make a shooter worldwide deployable with no requirement for data/zeroing under new conditions. They dramatically shorten training time, and solve instantly for problems that traditional methods often find challenging at best.

 

[Graham]

Sterlok+ vs JBM Elavation Solution is off up to 1 MOA at 1000yrds

No program can substitute for DOPE.

At 1000 yards and under, mine do.

I use FFS for ELR, but Strelok Pro most of the time.

 

[bogeybrown]

It's nice to hear some of y'all "admitting" to the solver-love.

I shot DOPE most of my life.

A few years ago when I was home for a few weeks, I went to a LR school with a brand new rifle. I came from sea level where I put a rough 100yd zero out to the Tx Hill Country, and with a ballistic Kestrel I was shooting out to 1200yds with absolutely zero DOPE for the rifle, or the range. THAT is not possible without a solver. Further, with my trued solver I know that I can take that rifle anywhere in the world and be on target with it, again, not realistic with pure DOPE. I brought a brand new data book with me to that course, and didnt' write shit down. I was pissed at myself afterwards, but I realized that nothing I could have written down would have been as accurate as what my solver was telling me. Mentally I was calling/plotting shots, but I wasn't messing with a book.

Where I agree with XTR is the intimate knowledge of your rifle and it's behavior under certain conditions. Years ago at Quantico I realized that I had a POI shift from sitting to prone at 300yds. While shooting for record, I cleaned the slow fire at 300 and then elected to make a sight correction from sitting slow to prone rapid. If you're off on rapid you're off for 10 rounds. I trusted my DOPE and went possible on the rapid. Without the DOPE I would have dumped 10 rounds.

 

[Shoots 700's]

I usually use jbm to start off, it gets me close. Once I fool around and tweak the data I use what works for the gun

 

[Lowlight]

Have to agree with CoryT and disagree with those who say the BCs are the problem.

You do exactly the same amount of work regardless of whether you use G1 or G7, they are saying the same thing. The only difference is, Litz is giving you an average and the manufacturer is giving you the highest value they can. After all the higher the number for them, the better, but it doesn't change the fact an Average does not suit everyone so they both have to be tweaked.

The difference is, You the shooter, and your System. You are not telling the computer exactly what your barrel twist is, you are averaging your MV and it might have a 5% or more error rate, your scope, your style of shooting, all play a role. As well the bullets have variations which also can change the BC from lot to lot ever so slightly.

This idea that some how G7 is doing something G1 is not, is nothing more than marketing hype. For how many years has G1 been the law of the land, and during that same amount of time G7 existed. There is reason G1 is called Ingalls... it's modified to work, so this purist definition is not exactly correct. The benefit is, how the software was written and the fact Bryan is doing some extra work to determine a better average as compared to the manufacturer data. Still he is not giving you an average based on 10 different rifle / barrel / scope / shooter combinations.

Once the software is calibrated to your system which includes you, then you can expect better than 1 MOA accuracy on a consistent basis. But 1 MOA is damn good out of the gate. Cause' let's face it, the data we are feeding the computer is at best a bare minimum and the horsepower under the hood of your smartphone is not exactly up to doing 6 DOF calculations. The averages used to help the computers along also matter as they can't account for every variable. 1 MOA is more than acceptable to start. You still have to do your part, there is no shortcut to the process except we don't have to do the long hand math or conversions thanks to the software.

Lastly, different writers of the software will slightly modify things so not all software is going to agree.

 

[NachtKracht]

Just a tad off-topic question to the TS:

The number of velocity, is that something you measured or just a nr you wanted to use for demonstation purposes about your solution question?
Because if you are getting 2950fps from 208 amax out of a 308w, i am very interested in your powder type/ brand, how much grains, barrell lenght and if you are living on top of the himalaya or not....
Just curious.

 

[LastShot300]

While advertised BC's may not be perfectly accurate, I would not go as far as to say they do not represent reality, just that they are not going to represent a perfect value for YOUR rifle/load. You are not going to see any improvement in reported solutions by using a G7 vs a G1 at ranges under 1K unless the solver is junk anyway. There is a string possibility that there is some small mismatch in data entry responsible for the difference shown.

I take strong exception to the statement that no program is a substitute for DOPE. Quite the contrary, good programs completely replace traditional DOPE/log book solutions and make a shooter worldwide deployable with no requirement for data/zeroing under new conditions. They dramatically shorten training time, and solve instantly for problems that traditional methods often find challenging at best.

+1

Couldn't be more well put. I completely agree. Data books are tools of the past for most real LR and ELR scenarios.

 

[LastShot300]

Have to agree with CoryT and disagree with those who say the BCs are the problem.

You do exactly the same amount of work regardless of whether you use G1 or G7, they are saying the same thing. The only difference is, Litz is giving you an average and the manufacturer is giving you the highest value they can. After all the higher the number for them, the better, but it doesn't change the fact an Average does not suit everyone so they both have to be tweaked.

The difference is, You the shooter, and your System. You are not telling the computer exactly what your barrel twist is, you are averaging your MV and it might have a 5% or more error rate, your scope, your style of shooting, all play a role. As well the bullets have variations which also can change the BC from lot to lot ever so slightly.

This idea that some how G7 is doing something G1 is not, is nothing more than marketing hype. For how many years has G1 been the law of the land, and during that same amount of time G7 existed. There is reason G1 is called Ingalls... it's modified to work, so this purist definition is not exactly correct. The benefit is, how the software was written and the fact Bryan is doing some extra work to determine a better average as compared to the manufacturer data. Still he is not giving you an average based on 10 different rifle / barrel / scope / shooter combinations.

Once the software is calibrated to your system which includes you, then you can expect better than 1 MOA accuracy on a consistent basis. But 1 MOA is damn good out of the gate. Cause' let's face it, the data we are feeding the computer is at best a bare minimum and the horsepower under the hood of your smartphone is not exactly up to doing 6 DOF calculations. The averages used to help the computers along also matter as they can't account for every variable. 1 MOA is more than acceptable to start. You still have to do your part, there is no shortcut to the process except we don't have to do the long hand math or conversions thanks to the software.

Lastly, different writers of the software will slightly modify things so not all software is going to agree.

Another perfect sense explanation, short and to the point.