That is perfectly normal. I have a PS90 and it is the same. I think it has been mentioned in at least five different threads on the fivesevenforum website. I believe this allows the barrel and chamber to move back with the bolt a little, maybe 1/32 of an inch. This allows the pressure to drop a bit before the case begins to be extracted.
Since the barrel floats it is important to not have anything other than the attachment of a 3 point sling touching the barrel. Don't rest the rifle on the barrel when shooting from a bench.
Other normalities:
1. The stock sight is terrible under certain conditions.
2. The finish on the receiver isn't so hot: rough looking casting and paint.
3. The paint on the receiver where the magazine rubs on it will come off.
4. The upper portion of the stock just behind the magazine will look kind of rough and the halves may not join straight. Mine is like this and I posted a picture on the fivesevenforum. The folks there said it was normal.
I guess the rough finish is because this is a combat weapon, not a safe queen. The sight? I can fathom why they don't change the sight. I got a 2x Compact ACOG because it will mount low with a custom mount. I don't have the mount yet.
The rifle is fun

That's the most important thing.