Strelock Pro and and slope angle?

[RMS65]

I'm struggling with Strelok and couple of my guns. I'm shooting down on to a field from my back deck. I have targets set at 160, 240, 320, 500 and 625. The 160 targets are about 80 vertical feet down. As the distance increases the elevation difference 5decreases. I've lazer ranged all the targets in both directions. I've also used two different angle compensating rangefinders.

My guns are Tikka 223 and 22lr. The guns are reliably accurate.

The 22 was zeroed at 50 yards. It shoots about a 3 or 4 MOA higher than Strelok calls for at 160. If I zero at 160 the 240 and 320 fall in line.

The 223 is zeroed at 100 yards. The 223 hits higher than its supposed to at 160 also. It calculates fine at 320 but fucked if I know where the 500 yard shots are landing. The same gun had no problem hitting 500 when shooting Hornady Match 75 HPBT. I'm shooting Fiocchi cased 77gr SMKs. Its more accurate with these from 100 to 320. I just can't find the 500 plate.

Somewhere my calculations are being thrown off. Since the calculations are off on both guns at the steepest angle targets. I'm wondering if there's more involved with Slope angle than the rangefinders compensate for.

Thanks