I sight in all my guns using a Ransom Rest and as long as I do my part, the POA and POI are the same. If they aren't (like in the case of older S&W M&P's it's because the timing of the barrel is off and the barrel starts to move prior to the bullet exiting. This is why Apex redesigned the M&P barrel.
Also: anyone who uses the excuse that it doesn't matter as the gun shoots better than I do has not spent much time looking at guns with a Ransom Rest. There is a huge difference in accuracy from gun to gun whether it's production or custom. Many things contribute from barrel lock up to the load and OAL of the bullet, but I can tell you there is a big difference shooting a Steel Challenge when you have a gun capable of 1" at 25 yards vs. on that shoots 3" at 25 yards. I may get flack for this comment, but this is what I have found and have actually sold guns that don't hold up to what I believe they should. For example I had an STI DVC Limited that was only capable of 2 1/2" at 25 yards no matter what I did. I now have a 2" threshold where I will get rid of any gun that won't hold that after load development and/or mods. I have a Glock 34 with Bar-Sto barrel I fitted that will shoot 1 1/2" at 25 yards, 2 CZ Compacts that do the same and I can get 1" out of my Atlas Gun Works Titan.
Bottom line is, if the gun doesn't have a design flaw, it should shoot the same from a Ransom Rest as it does in your hand with proper trigger control.
