Maybe a dumb question about p o i

I have a wildcat MK2 30 cal. The other day I removed the factory moderator and put a Donny FL Sumo on it. Now at 25 yards the pellets are hitting 1.5 in below the bullseye in 1 inch to the right of the bullseye, before I changed it I would get one hole groups. Now I know going from not having any moderator to putting a moderator on will change the point of impact but could changing the type of moderator change the point of impact?
 
Put the donny back on, stick a piece of insulating tape over the exit hole, fire one shot (ensure your gun is safe) and inspect the exit hole from the pellet, it should be plum centre to the hole in the mod.

A heavier mod will cause the barrel to drop and will alter the barrels harmonics, inevitably the poi will change.

where possible, I have a preference for a shroud, not only do they give more volume for better noise suppression, they add stiffness and are less likely to cause clipping issues.



Bb
 
Okay, chew my head off. Donny is making quality products and is one heck of a dedicated supplier and aide to the sport. He deserves our loyalty and support. having said that, I have a couple Huggets. I am MORE THAN SATISFIED, to saw the least. I have not had a Donny. So, I'm just saying. it could be worth a comparison test on your particular problem.