I bought a new box of Federal 160gr Accubonds for my 7mmRemMag today and noticed that they all had a cannelure.....I didn't remember seeing this before, so I looked at an older box and found that I was right, as the older bullets were smooth and without the cannelure.
Any of you know why this is, as I thought that the bullets should be consistant and exactly the same. Does this make any difference, and why did Nosler make this change.

FWIW, I've noticed some factory loaded .338 Partitions with the cannelure, whereas the bullets sold as components do not.

The reason they are cannelured is so that the factory can "crimp" them. Nice smooth bullets in new virgin brass tend to slip and crimping holds them in place.

I do beleive Federal requests the various bullet manuf. to put cannelures on the bullets to be used by Federal.
the componet bullets as we buy off the shelf will probably have no cannelure on many of the bullets.

You'll often see crimp grooves in partitions sold as 2nds at the Shooter ProShop. Like Southpaw stated, each ammo manuf. has their own requirements.

The old box were also Federal's, the one's without the crimp.
So the bottom line is that it dosen't matter, Am I correct on this??

I won't say that it doesn't matter, as I have always felt that a cannelure tends to very slightly degrade a bullet's accuracy potential. After all, the process of rolling it on introduces some stress into the jacket that one would think must be reflected in some way in the jacket's interaction with the bore.

Think about it: How many match bullets are cannelured?

Now that that prejudice has been expressed, I would add that it is doubtful that you can tell the difference in most hunting rifles, especially with (choke, cough, cringe) factory loads.