I’m moving from an 11.5 inch to a 14.5. Will the barrel length alter the POI based on my current zero? I’m thinking it wont but wanted to get others thoughts. Either way I will still be going to the range to confirm my zero.
Yes…
Ummm, yes.
And it would still be yes if you were switching to another 11.5" of the same brand and specification.
The different barrel will change your zero regardless of length. It’s a different barrel for crying out loud. Your AR is not a platform designed for interchangeable barrels that will return to zero with their sights or optic.
When you replace the barrel you will be altering the alignment of the barrel to the reciever, and while imperceptible to the eye it will be very different down range. Even pulling the barrel and putting it back on will probably have you re-zeroing.
It’s funny…I read this and just kind of rolled my eyes, thinking of course you do. Then it dawned on me, is a LMT MRP any different? I don’t have one, just curious if it is possible that they could return to zero after removal and reinstallation of the exact same barrel? Anyone have one that knows?
Ah, yeah… you will…
Well if you want to hit what you are aiming at, you will… 
Exactly…
I completely understand this will alter my exact zero at where it is now but to what extent? Are we talking minimal shift or inches?
It depends.
ok…. So there is no one that has actually done this that can talk about results?
Barrels and where they will zero is kind of like magic. Literally no one can tell you how far your new barrel will be off of zero. If you had two identical barrels and swapped between them, you couldn’t predict the shift of one based on the other. If you remount the same exact barrel, you’ll see a zero shift.
So going between two different barrel lengths isn’t going to be predictable at all, by anyone. Sorry.
Why don’t you try it and tell us what you find out?
We’ve told you what we know and think, now the ball is in your court.
Yes, I have changed barrels on several ARs. I have always needed to rezero them.
Oh yeah? Watch this.
New POI ,if zero’d at 50 yards, will be 1 inch high and 1 inch left. Multiply by 2 for hundred yard zero.
What’s really going to blow your mind is when OP goes to range and finds out I’m right!
That’s my guess. Any other wagers?
At 50, 0.42" right and 1.29" low.
I’ve been more than a inch off just by breaking torque on the barrel nut and going 5 pounds heavier upon re torquing.
Assume nothing.
Its already understood there will be a need to re-zero. Hell if i take my QD optic off the rail and throw it back on there will be shift and it should be re-zeroed. My question was in hopes someone actually did it and could give a description of the outcome being waaaaayyyy off their original zero or slightly off. There is a way to predict the outcome if someone has actually done it…will it be exact? of course not
nawww I’m just gonna take everyones word for it and call it a day
I have done it, and it was off considerably. There is no “constant” if that is what you are looking for. I suggest you do it yourself and then you can find out first hand.
Closed since the OP is playing some weird baiting game and not wanting to accept the what was pointed out.