Ok...so here's the quick rundown. S&W 460, 7.5" barrel. Mounted a Burris handgun scope to it and took out 4 types pf ammo (all 460), started at 50 yds:

Hornady factory 200g (claim is 2200'ish FPS)
Hand load Berrys 250g over 13g Trail Boss (no chrono)
Hand load Hornady XTP MAG 240g, chrono'd at 1900 fps ave
Hand load Hornady XTP MAG 3000g, chrono'd at 1700 fps ave

So...to get on paper at 50 yds, I started with the super light 250g Trail Boss loads. I got on paper, swapped to the factory 200g XTPs. To my surprise, they shot near identical POA as the mouse fart Trail Boss 250g.

Ok...move to the 240g...and I'm about 11" high. Wow, ok, move to the 300g and once again, 11" high and near identical POA as the 240g.

I go back and forth between the ammo and the results are the same. 200g and 250g, same POA. 240g and 300g, 11" high but same POA.

I get the POA of the 250g slow loads being way off from the faster loads...but the Hot 200g being the same as the light 250g and the hoter 240g being the same as the 300g...and those two groups showing a 11" difference is new to me.

I plan on shooting the 240/300g the most, so in the end I used that as my zero. Going back, my light plinkers and those Factory Hornady 200g are now 11" low from POA.

I'm stumped.

I am not an expert but would guess your problem lies in the heavier recoil of the latter two rounds.
The instant the charge ignites your barrel will start an upward path from the recoil. Heavier loads will react in an exaggerated fashion from the lighter recoiling loads.
I may be all wet. Hopefully someone better versed in such issues will chime in and we can both learn something.

Heavier rounds will typically have higher point of impact due to 2 primary considerations working together, assuming the same gun.

Heavier loads (bullet and powder) produce increases recoil reaction and the speed of the bullet is decreased. The bullet is now in the barrel longer (dwell) and the recoil produces a higher barrel trajectory. Net result is a higher point of impact.

__________________
be safe
Ruggy

This is correct. Shoot those heavier loads at longer range. You may find that the lighter loads are dead on at 50 yards and the heavier loads are dead on at 150 yards or so. Perfect for ahunting revolver. Without having to adjust your scope, if you are going for close range or long range, just grab the lighter or heavier load. Most of the time light bullets and heavy bullets will shoot to the same poi if the powder charge is the same. The increase in recoil of the heavy bullet raises its poi automatically compensating for the lower velocity. The decrease in recoil and time getting out of the barrel automatically compensates for the increased velocity of the lighter bullet. Best of both worlds!