Question for Xbal users

[RDM416]

I just got my copy of Xbal in a few days ago and began loading data into it. Although it is closer than other ballistic programs I have used I am having problems getting it to match up with the real world.

I am shooting a 338Kahn with 250grn SMKs at 3170fps. Sighted in exactly 3" high at 100 yards. Using a NF NXS scope.

I have shot on several occasions at 100 yard increments out to 1000 yards. I have refined my dial up chart to the point I am very confident in it.

When I plug in all the data Xbal agrees with my dial ups exactly out to 700 yards. At 800 and 900 Xbal tells me 1 click more than my chart. At 1000 it tells me 3 clicks more than my chart.

Am I just being too picky? 3 clicks when you are talking about 70+ clicks is not much, but 3 clicks at 1000 is enough to miss a deer sized criter.

I can adjust the BC from .587 listed by Sierra to .610 and I am on at 800 and 900 and 1000 is only 1 click to high.

Any words of wisdom from all you that have been using Xbal for a while?

[CAM]

RDM416
No problem just hunt Elk there bigger!!

Most times the match is not perfect,
One way to tweek the BC

There is a place to adjust the BC for different FPS
example. 3000FPS BC.610, 2800FPS BC.60, 2600FPS BC.58

Also I like to get the longest range to match and the close differents is usually small.(1/2MOA at 200 VS 1/2MOA at 2000)

Tweek away
CAM

[Black Diamond 408]

From what i have seen, you do have to correct the BC of the bullet your using. Factory listed BC can be very different from what your rifle is producing. The 300MK bullets out of my gun is closer to .810 than the factory listing. But like you have done, the gun has to be shot at varying increments to see what the actual drops are. Exbal is a very good program.

Dave

[RDM416]

Thanks for the input Cam and BD408.

From my limited experience so far, I really like Xbal. I don't know why I waited so long to get it! [img]/ubbthreads/images/graemlins/smile.gif[/img]

Good point Cam about adjusting things (BC or other vairiables) to get the long ranges on, then not worrying so much about the short range. 3 clicks off at 200 is pretty negligable for deer and elk sized critters, but 3 clicks off at 1000 is several inches.

Thanks BD408, it sounds like I was on the right track by adjusting BC to make everything come out right. It is good to have someone with your experience confirm that.

[RDM416]

Cam,
I forgot to mention on my previous reply.........I am leaving next Wed for southern New Mexico to elk and black bear hunt. [img]/ubbthreads/images/graemlins/grin.gif[/img]

Lots of open country where I hunt so there are lots of opportunites for long range shots. If not at an elk or bear at least at a song dog!

[Shawn Carlock]

RDM416,

Have you run your real data through the trajectory validation page in the Exbal program to justify it?

[RDM416]

Shawn,

No, I have not. I did not know there was such a section in Xbal. As I mentioned I got it in a few days ago and just jumped in and started plugging in data. My wife would say "typical man". Instead of reading the instructions and learning the program, I just jump in and start using it. Then I am confused when everything does not work the way I think it should [img]/ubbthreads/images/graemlins/grin.gif[/img]

Thanks for the input Shawn, I will spend some time this afternoon exploring ALL the features of Xbal!