help me understand....

[scion19801]

so i have my condor. got it tuned finally and custom ldc. thing is silly quiet now. I'm averaging 860 FPS with 29.2 NOE hunter pellets. Sighted in at 33 yards. i did have to shim the scope to get better centering on the turrets. then put all this into chairgun. using .373 for bc. but when i actually go for distance 100 yards. I'm way off. i basically have to hold at the center ( 3rd mil dot) which should be my 78 yard position. 1st mildot down is my 50 yard and that lines up no issue. 2nd is 68 yards no issue. so y would my 3rd get so far out of whack. Is this a scope issue? is it due to the condor spinning the pellet faster with it having a 1:16 twist rate that is is giving the pellet a way better bc?
 now with all the same settings basically in chairgun it lines up perfectly for my gauntlet. that is slinging 28.2 grain NOE hunter pellets with a bc of .373 that is at 878 FPS average. All mil dots line up perfectly on that scope.
I'd like to get a better handle on the condor as i would like to get it out in the woods, but things aren't meshing up well with it past 50 yards. And no it definitely isn't a clipping issue as my custom LDC is properly made after 3 revisions. all baffles interlock with each other and can't shift around, and my pellet hole through it is 7.60mm for a .25 cal.

[dmeguy]

You're missing a zero in the estimated BC. It should be .0373.

[scion19801]

Opps. That was a typo. There is a zero there. It does read .0373 for the bc. My bad. But the issue is still there.

[Fate]

Dan, here is a link to a solution for a common issue that has a critical effect on ballistic programming. It helped me.

https://airgunaccuracy.wordpress.com/chairgun-and-scope-height/

[scion19801]

doouh. how did i overlook that? so it appears that my scope is 2.6" above bore center on the condor using a 1" dai scope with medium height hawke rings. man that is a big jump over my gauntlet. the gauntlet is 1.86". it is definitely closer to be on target at distance. still off abit. so its finally getting to be closer to corresponding with chairgun.

[scion19801]

found my issue finally. it appears that even though the manufacture of my scope says 10x for accurate mildots, after doing a calibration check with chairgun it appears that 12x is where it needs to be calibrated. then when i drop back to 10x everything is lining up and working out well now. the scope is a cheap nikko stirling mountmaster 4-12x50AO. trying to locate another good deal on a hawke 3-12x44 sf with 1" tube.
I just recently put one on my gauntlet and it's a tack driver now.