H&N FTT .177 Ballistic coefficient?

[AudiS4]

And just to make things even harder. 

BC for H&N FTT is 0.22 at a given fps. For example, a 900 fps and a 650 fps shot, have a significant difference in BC for the same pellet.

[linoww]

And just to make things even harder. 

BC for H&N FTT is 0.22 at a given fps. For example, a 900 fps and a 650 fps shot, have a significant difference in BC for the same pellet.

I didn't think there was a significant difference once everything got subsonic. I do not think it would be a 30% difference anyhow.Anyhow both are well below Mach 1. I would imagine  they calculated their ballistic coefficient  somewhere near 750 fps.

So far my target data backs up the .022 BC.
I can't see any arguments over that.