I need advice,
I sighted in my new leupold scope today on my 300 blackout with 110gr.v-max at 25yrds.
Then moved 75yrds.to do a final zero with 130gr.Hog Hammer Barnes bullets which I intend to shoot only for hunting from here on ....
Once I had the scope zeroed with the barnes 130gr. bullets I fired a 5 shot group with the 110gr,vmax just to see where they would land.
The 110gr.v-max were 4 inches high!
Does this sound about right for the 300 Blackout ammo?
I would have never dreamed a 20gr.difference would group that much off....it pays to check these things on paper .

It's both the bullet weight and the velocity the bullets are moving at that gives you this difference.  The 110gr bullets are built to go fast; Hornady quotes a muzzle velocity for their factory ammo at 2375 fps.  The Hog Hammer bullets, on the other hand, are built to hit hard; Remington says their muzzle velocity is 2075 fps.  That 300 fps is a big difference by itself, but then it's not the whole picture.  The 130 gr bullet is not as streamlined as the 110, and will have a lower ballistic coefficient (more drag).  So that 4" difference at 75 yards is because the lighter, more streamlined bullet is going much faster, while the heavier, less streamlined bullet is going slower - and will slow down more rapidly.

Basically, that's "pretty reasonable" for differences in bullet weight and profile with the 300 Blackout.  It does make you understand the value of hold over tables and scope cheat sheets when you shift form one round to another.

Edit to add: I should add that Hornady explicitly states their muzzle velocity is based on a 16" barrel, and while Remington doesn't come out and state their test barrel length, the standard length for 300 Blackout test barrels is 16".

Thanks bigtime for the help!

On top of GHPorter's advice I suspect this has more to do with barrel harmonics more than anything.    Different barrels will react differently to each ammo load.   For instance many people may have their rifle sighted in with a certain brand/weight ammo.   Now they can't find that specific ammo and look for another brand with the same weight bullet expecting the POIs to be very similar.   Sometimes it works and sometimes it doesn't.   That's why it is generally important to sight in each specific round to your gun.