You may get a little muzzle brake "pull-off" effect.
It's frustrating until you figure out what exactly is happening
especially if you have never shot rifles with muzzle brakes before.
At 100 yards, the bullet likely has not "settled down" yet
so I would not worry too much over 100 yard groups.
One day I took my Sako 995 .338 LM to the range.
By the time everyone that just had to try it out did, I counted up the
brass and figured out that we went through $250.00 worth of ammo.
That said, there is an addictive quality to the .338 LM that most anything
smaller will not satisfy.