Chairgun/Strelok change the velocity or the pellet BC?

I got my F1 Chrony and was excited to see what my gun is shooting at. I am shooting a stock HW95 .22 caliber, with H&N FTT 5.53 head sized pellets at a published 14.66 grains and .019 BC. My scope height is 1.5 inches.

I shot a 10 shot string and got an average of 685 fps, which seems consistent with other results I have seen published online for the HW95 and the H&N pellets. I shot another 10 shot string over the crony with an average of 686 fps and a spread of 3 fps. I am shooting from my covered patio with natural sunlight. I moved the chrony around the yard with similar results at different lighted locations as I read the F1 can be light sensitive.

I am sighted in at 30 yards and used the validation program on both Strelok and Chairgun, both are showing I should be hitting about 8.1" low at 61 yards. I shot 5 shots at 61 yards and am hitting 7.5" low at 61 yards. So either my velocity is wrong or my BC for the pellets is wrong? It shows that the adjusted velocity should be 707 fps, or the adjusted BC should be 0.0225. What would be the better value to change, I am thinking the BC as the chronograph should be fairly accurate? Changing either value gives the same results and the hold overs in my mildot scope seem accurate per the chart.

Has anyone else with the H&N pellets showed a higher BC than published? I am slowly gathering my variables for the best entry into the programs, but am trying to figure out the variances.

Thanks!
 
Me personally, I would calculate my own BC using the calculator in ChairGun. I was using my old Benjamin marauder .22 shooting the JSB 18.13 grains which they say has a BC of 0.0330. Once I got my numbers from the chrony at the muzzle and 50 yard my BC ended up being 0.0373. Granted that's not much of a difference but when doing the Strelok calculations it will make a difference. You will find that most of the time you have to find the BC for your specific rifle since there are sooooo many variables involved. Just my 2 cents. Hope this helps 
 
I went ahead and used the chairgun .029 and 14.8 grain weight pre-set for the FTT pellets. With chrono results and the chairgun values it came out perfect showing 7.5" drop at 61 yards, exactly my results. I will shoot at 10 and 15 yards tomorrow to further confirm, but my field mapping results all seem to match chairgun now. I will put these same values in Stylok as well.

Thank You! It is nice when the values all seem to work out, it gives me confidence in the tools and gun.