Neck is not fitting in pocket


Received my body (alder) and neck (maple with rosewood) yesterday from Warmoth.  This is my 2nd build.  The finish is beautiful again on both pieces.  Went to test fit the neck and I cannot get it into the pocket.  It seems that the neck pocket is a hair too small and I can hear the wood straining as I try to fit it in.  I am not sure about exactly what to do besides calling Warmoth for tips.  I am assuming that I will have to sand the sides of the neck pocket down a bit to allow it to fit in.  Any ideas or tips??
When I received my body and neck I had the same problem.  I think it's just due to the finish on the neck adding that tiny bit of extra width to the neck.  I sanded down the sides of the neck pocket.  It didn't take much, then the neck fit in snugly.  Good luck!
Thanks for the reply and sorry if I sound like a dope but what grit sand paper did you use, does it matter?  Do you mask anything off?
I'm not sure exactly what specific number grit I used, I just know it was medium grit.  I didn't mask anything off (though I probably should have, just to be safe) and I used sanding strokes that started on the outside and moved towards the middle of the body.  Hope that helps
yeah, thanks it did.  I got it snaded down a bit and everything there is fine.  Now I got to deepen the nut slots on the high e and b strings as they are not deep enough and the strings are popping out on low bends......the first neck I received from Warmoth was a lot better in terms of these issues
That's intentional.

You should have to sand a bit to get it to fit, because you want it to fit rather snugly for a couple of reasons.

1)  To secure proper alignment, and prevent shifting when moving around with any degree of agility.
2)  To aid in transferring vibration from the neck to the body.  Tom Anderson Guitarworks referrs to this as a "constant pressure union".

I've had poorly made bolt on guitars when I was in my early 20's (many moons ago) that had the necks shift just from jumping off of a drum riser to the floor, like 2 ft.  With a tightly fit bolt on neck, this should not happen.
I wouldn't be surprised of the neck wood swelled or body wood contracted during shipping (wood does that). I'd rather have it too tight than too loose. Like everyone else said, a little sanding should fix a problem like that...