I think it's the VTF flag called Point Sample that isn't checked.
It's a disadvantage of using the ql_ and cpma_ crosshairs because none of them have the flag.
It actually helps with dots and wings imo because the bit of blur makes them look less jagged, but for crosses I prefer having it on.
Here's a fixed cpma_12 https://www.dropbox.com/s/sgxoyqok7yl9vgb/cpma_12.vtf?dl=0
Maybe the flag behaves differently depending on dxlevel? I'd have to do some testing
here's a comparison of a different crosshair on large crosshair scale. Both are on dx9. I just made my grenade launcher and stickybombs the same crosshair, but one with and one without the flag https://imgur.com/a/jEddFl1
edit: for anyone wondering what I changed
open the VTF (I use a plug-in with paint.net to edit VTFs directly. You can also import VTFs using VTFedit).
Then save the VTF with Point Sample, No Mipmap, No Level of Detail, No Minimum Mipmap and Eight Bit Alfa.
Point Sample is the only optional one. Those other ones are needed for any VTF crosshair