Think I have run into a problem here!!!

[dwm]

Not that I know anything at all about this, but if I put all your posted data plus a barametric pressure of 29.25 Hg in Load From A Disk I get 115 MOA ...

That will cause the corrected BC to go to 0.71 and require more MOA.

Is it possible the pressure was 29.25 Hg?

Doug

See e-mail ...

[MachV]

Fifty
Couple of thoughts.
#1 I am surprised you haven't adopted the practice of keeping the rounds in you're inside shirt pocket.Seams to keep the velocities even for me.
#2 Don't know about your Wild but mine needs recalibrating with much of a temperature change.My Wild come with a real dark lens that I use to calibrate it to the sun.Not sure if this is the best way but it seams to keep it reading consistently for me.The Wild gets real touchy at that range too,I usually take three readings and average?
Still 25MOA is a lot???????

[Fiftydriver]

Today I was able to take some time at lunch and set up my Wild rangefinder and check it against my Swarovski laser rangefinder. This is usually how I check the Wilds calibration as the swari will reach out to 2K in good ranging conditions.

To day was not the best conditions to range but I used a corner of a shop across from our property to range. Set the Swari to the meter reading setting and got five readings off the shop, 1072, 1073, 1072, 1072, 1071 meters.

Then set up the Wild and took several readings with it and got the following: 1011, 1010, 1012 and 1015 meters.

So at this range, the Wild is basically reading 60 meters short. If this error held true which it may or may not at longer ranges. I would suspect the error would even increase at longer ranges with this type of rangefinder but even if it stayed consistant this pretty much solves the mystery.

I was set up shooting at a measured 2450 meters measured from the Wild range finder. After finding that the Wild is ranging short, if it holds consistant over this range, the actual measurement in meters would be more like 2595 meters.

In yards, I was shooting for 2680 yards and in reality, the gong was more like 2840 yards away. A difference of roughly 160 yards which at that range is very significant.

Combine that error in range measurement with the fact that the actual muzzle velocity was probably more like 3350 fps instead of the 3395 fps used in the Exbal program and things come into focus and look much more logical as to why the shots dropped so low from the start.

Time to recalibrate my rangefinder and see if I can get her to match up with the Swari again. She was last summer so it must have gotten knocked out of calibration or the colder temps have something to do with it.

Thanks for your time and help, I think the problem has been found!!!

Kirby Allen(50)

[NesikaChad]

Interesting, but I am drawn to ask a question. Has the other (Swarovski) unit been calibrated as well?

Would/is it possible to maybe obtain a US Geological survey map of your area and combine it with a GPS unit to plot the distances and verify your readings that way?

Another rough gestimation might be bouncing it off of your come ups on your elevation based off of a table and see if you are in the ball park that way. I/E 200 minutes of angle increase in elevation on that cartridge yeilds a theoretical zero of 2500 yards. . . If you were within a couple minutes of what it suggested, it might back up your other findings.

(or cause even more "scratching head syndrome.)

Makes this stuff so much fun!

Just a thought. . .

[edge]

Since I have never shot at a distance where the bullet went subsonic I can't say what would happen, but it seems that your bullet past the transonic zone somewhere between 2400 and 2500 yards.

Does Exbal calculate any effect of this?

thanks,

edge.

[Fiftydriver]

NesikaChad,

I have tested the Swari from one full section fence line to another across a stubble field that was about as flat as muy desk top!!

Put a truck on one fence line, drove to the other and took some range measurements off the truck. Came within 5 yards of a mile on every measurement. I was actually surpises the fence lines were that close to on!!!

I then tested the Wild against the Swar out to 2000 yards and they were on the money at that time. Something must have knocked the Wild out of calibration.

Thanks for the recommendations, I guess great minds and crazy people think alike!! [img]/ubbthreads/images/graemlins/grin.gif[/img] Using those two groups of people I do not offend you while correctly representing myself!! [img]/ubbthreads/images/graemlins/blush.gif[/img] [img]/ubbthreads/images/graemlins/grin.gif[/img]!!

Kirby Allen(50)

[Fiftydriver]

At my altitude my predicitons are a bit more range then this at supersonic velocity. Around 2600 yards at my altitude.

I do not believe Exbal does not take into acount any change in bullet flight under supersonic velocity compared to over.

Kirby Allen(50)