Sierra software

[newton]

Does anyone have the Sierra Infinity software and could look something up for me?

[country gent]

Maybe post what you want researched on the program so people know what thier getting into? Along with the request.

[newton]

Maybe post what you want researched on the program so people know what thier getting into? Along with the request.

ok, I want to see if what they claim is true. I want to have someone put in a load, then be able to compare it to the same load but with a different velocity. This would change the zero point for the second load.

Sierra told be the software could do it, but they also made it sound like it was a PBR calculation - which its not.

Anyways, that's what I am looking for, nothing too complicated or worthy of much caution.

[country gent]

Okay, I have used the sierra infinity program in the past on a lap top. This enabled me to help with the ORPA 1000 yd match during sighn in and the new shooters that didnt have a 1000yd zero. Given good data by the shooters as to bullet, BC, velocity and other info the program normally was inside the 9 ring usually 10 ring. I did alot of calculations for same caliber (308) diffrent bullets same basic velocity, same bullets diffrent velocity, and diffrent calibers 243-300 win mag. The amount it gave to come up from 200yd zero was very close if acurate info was plugged in. It takes more velocity than some think to make a full minutes diffrence in elevation ( not figuring barrel harmonics and other factors). Most of the people I gave info to were inside the 9 ring if they counted up corectly and gave me good info.

[newton]

I figure their software is good, but I just am curious about one specific thing. I can't remember the name, but the one software that I tried does it by taking the first load and applying MOA adjust to the second load. Or something like that.

If I knew they would refund my money I'd just buy it and try it. I'm just wanting to decide which program to get.

[chutestrate]

Let me know what you want researched, and I can email you the results or post here.

[newton]

Let me know what you want researched, and I can email you the results or post here.

Pretty much just a trajectory table that shows two rounds that are identical except the second having a velocity 800 fps slower. The zero range would need to be set for the first round.

Hope this makes sense. The idea is to be able to zero your scope for a hunting round/velocity and then approximately gauge where lower velocity plinking ammo would hit without having to change scope settings.

Thanks.

[Rick Hodges]

I had the Sierra program but currently use one called "Point Blank". Both were very accurate predicting trajectories of a given bullet at a given velocity...and are useful for predicting trajectories from different velocities.....but:
None can predict zero with different loads. Two loads with different powders that produce the same velocity do not necessarily have the same zero. The rifle/weapon reacts differently to pressure curves and or vibration nodes. The loads may or may not have the same zero. I guess what I am saying is that the programs can predict the trajectory of your two loads but the plinking load may have an entirely different zero...once zeroed you can predict drops at other ranges.

[newton]

Yes, that's the point really. Lol

They undoubtedly will have different zero points. The whole reason is to see where the second, slower load, will have a trajectory with the scope remaining zeroed for the higher velocity load.

I have a demo version of a software that does this calculation. So I can see how it works, but if the Sierra program does it then I would purchase it. I would purchase the current program, but when I do load jacketed rounds I use Sierra bullets.

If chute can run the program with his Sierra software then I can compare it to the one I know for sure works and see if it does what they say it does.

The problem is, like you demonstrate Rick, that people don't seem to understand what I'm after. No offense, just my lack of ability in putting into words what I'm looking for. I feel the guys at Sierra are also misunderstanding me hince my reluctance to believe their software does what I want.

I know it seems irrelevant or insignificant in the grand sceme of things, but it's what I want.

[country gent]

well, ignoring the harmonics, barrel time, and other issues not able to be entered into program. If you load is xxxx fps with a certain bullet that is considered zero, then the sierra program will show the diffrence in elevation for the load faster or slower with the same bullet or diffrent bullets change. I know of no programs that can take into account harmonics and other external issues. Plug your existing load in as zero and then the new loaad and it should chat both loads showing diffrences.

[newton]

But will it show it with the higher velocity zero? Most programs put the same zero point to the slower load also.

i realize all the other things come into effect, but that's besides the point. We don't look at those other things when looking at a single load trajectory, no reason to just attribute them to a slower load.

[Rick Hodges]

It is a **** shoot if both loads will have the same zero. If they do the ballistic charts and tables will help you. I sight in my 6mm 2" high at 100 yds. and can use the tables to predict the trajectory (point of impact ) at any yardage I am likely to shoot. ( it has proven remarkably accurate out to 400 yds for me) If the 800 fps slower round shot to the same point of impact at 100 yds...It will predict the trajectory of that round. In the same manner.
The problem is: It is unlikely that your slower load will have the same zero...it may be higher or lower or even left or right. My experience has been that it is rare for my rifles to shoot two different loads to the same point of impact. Go ahead and try the sample program and the figures run for you, but I think you will be disappointed.

[country gent]

Once you get the first print out there is a way to "compare " other loads" to it. this is either a graph or chart with diffrent loads trajectories in diffrent colors. Or they can be printed in a table showing desired range increments ( every 10,25,50,100 yds to the desired range) the 2 loads superemposed on the graph show this easier since all the loads desired are on the same screen. The biggest thing is putting good data into the program to start with. Velocity, sight hieght, bullets BC ( dont believe all of them on the boxes as some are "off") Also Bcs change with a given velocity and as velocity changes in flight so does bc. How far above sea level, temperature, barometric pressures, humidity also have a direct effect here. The sierra infinity is a very good program as are some others out there. To do this as accuratly as possible will require also figuring the actual ballistic coefient for the given bullet.

[M-Tecs]

What you are asking is not realistic. Ballistic programs do very well with a known zero point. You are asking it to predict a point of impact based on changed variables without a known zero.

The math is straight forward. What you are asking for is the point that the bullet passes through the line of sight on the way up and on the way down. Line of sight is always the same and the angle of bore will be the same until the adjustments are changed so mathematical it's not a problem but the reality is barrel harmonics and barrel rise/projectile time in barrel still require an actual known zero to be accurate.

If you do find a program that makes theses predictions please post what it is. Mathematically it would be fun to play with but I would be very surprised if it worked in the real world.

[Doc Highwall]

It will only work if both loads are zeroed at the same distance with the sight height being the same. The program will now predict what your drop figures are going to be at what ever distances that you choose.

In order to get a good trajectory table you have to know the muzzle velocity, ballistic coefficient of the bullet, and the distance that the centerline of the sight is above the centerline bore, and a zero distance. Atmospheric conditions are also needed.

Even after doing all that work, it still has to be verified by actual firing due to things like barrel harmonics.

[SSGOldfart]

I had the Sierra program but currently use one called "Point Blank". Both were very accurate predicting trajectories of a given bullet at a given velocity...and are useful for predicting trajectories from different velocities.....but:
None can predict zero with different loads. Two loads with different powders that produce the same velocity do not necessarily have the same zero. The rifle/weapon reacts differently to pressure curves and or vibration nodes. The loads may or may not have the same zero. I guess what I am saying is that the programs can predict the trajectory of your two loads but the plinking load may have an entirely different zero...once zeroed you can predict drops at other ranges.
Hey Rick which do you prefer point blank or Sierra?