What is POI Shift?
We get a lot of calls from people who are concerned with POI, or Point of Impact, shift when using a suppressor. Unfortunately, a lot of people aren't 100% sure what that is, even though it's a very simple concept. At a high level, POI shift is simply the shift of the bullet when a suppressor is installed. It's typically measured in MOA (Minute of Angle) - so a POI shift of 2 MOA would indicate a 2" shift at 100 yards, 4" at 200 yards, etc... With suppressors, there are really 2 types of POI shift to be concerned with:
1. POI Shift When Mounting the SuppressorWhen you put a suppressor on, or take it off, you'll typically see some POI shift. We've run quite a few tests on this and have found that the initial POI shift tends to be more impacted by the threads on the weapon rather than the suppressor; so, if you run 10 different suppressors on the same gun, they will generally all shift in the same general direction. There are a couple of cases where you'll see no POI shift at all:
- If the threads on your weapon are perfectly aligned with the bore.
- If you are using a suppressor with a larger bore, it typically won't impact POI as much as a smaller bore suppressor. (It won't be as efficient as a smaller bore suppressor either.)
2. POI Shift from Shot to ShotThe second type of POI shift is a shift that occurs from shot to shot - and this is generally more related to the mounting system of a quick attach suppressor. Although mounting systems have improved a lot over the last few years; and, it's often possible to see the same accuracy from direct thread and quick attach suppressors, many locking quick attach designs will result in a loss of accuracy. That loss of accuracy is a result of the slight movement of the suppressor as it shifts on the mount from shot to shot. Because of this loss of accuracy on some quick-attach mounts, many accuracy shooters will only use direct thread suppressors because they don't have any shot-to-shot wobble. Some of the new compression mounts and small tooth mount systems are also starting to venture into the accuracy realm that was previously dominated by direct thread suppressors. Most modern quick-attach systems are capable of at least 1.5 MOA accuracy (i.e. 1.5" at 100 yards). Most people are shooting larger groups than that anyway - and typically won't see much, if any, change in accuracy. If, on the other hand, you're shooting 1/2" groups at 100 yards, you'll probably be disappointed if you're groups open up to 1.5 MOA. :)
ConclusionAt the end of the day, the initial POI shift isn't a very big deal in most cases. As we already mentioned, just put on the suppressor and re-zero you're weapon. For volume shooters, any modern locking system will be sufficient; but, if you're a precision shooter, we'd recommend sticking with either a direct thread model or a locking quick attach that uses a compression mount or a tooth mount with smaller teeth.