Point-of-Impact Shift
Also: POI Shift
A change in where a rifle prints on target when a suppressor or other muzzle device is added or removed, requiring a confirmed zero for each configuration.
Point-of-impact shift describes how a rifle’s group can move on the target when you mount or remove a suppressor, a brake, or any other muzzle hardware. Adding mass and length at the muzzle changes the harmonics of the barrel and the way it whips during the shot, so the bullet leaves at a slightly different point in that vibration cycle and lands somewhere other than your bare-barrel zero.
The practical rule is to confirm a separate zero for each configuration you intend to shoot, because a can that prints two inches low and right at one hundred yards will be far off at distance. A well-made silencer with a repeatable mount should deliver consistent return-to-zero when reattached, but you should always verify rather than assume that any muzzle device goes back to the same impact.