I recently received a full size mp9 with thumb safety. It says it was test fired in April 2014. Should the crown of the barrel be a perfect circle? Mine seems to have cuts and is more of a hexagonal shape but it's not. My brothers glock barrel is a perfect circle on the muzzle end and I was wanting to know if this is normal for the mp line or not. (When looking down the bore everything  looks fine, like it shouldn't affect the accuracy but I'm having some problems in that area, as I am new to center fire pistols it could be me . Just wanting to cover all my bases before I call S&W)

The crown of a barrel can absolutely affect accuracy.

Pics would help to know what it looks like.

S&W barrels use land and groove rifling while Glock barrels use polygonal rifling which makes the crowns look different. What you're describing sounds normal, but you can post a pic to be sure.

barrel

 

Thanks for the reply. I'm going to go to the range and work on my shooting now