Question about barrel swap

[JTB]

My point of impact dropped 5" on the same barrel (a 5.56 upper) just by swapping from a brake to a thread protector. I could certainly understand a change when swapping barrels. Different harmonics.

That has to be what it is. It struck me as odd. I had to walk down to my target to make what I was seeing was right. I’m going to let it ride. Thanks for the response. I have wondered about effects from different brakes.