YZ250 2015 new piston - ring end gap

I’m about to throw a new piston into my bike.

I put the piston ring inside the cylinder head right about 1-1.5cm down and measured the gap with a feeler gauge, I measured it from all sides (think square , front, rear, left and right) 

The closest I got to was 0.40mm and the most gap I had was 0.55mm. 

The piston is a B and same for the cylinder. 
Is the ring gap ok? 💪🏼

Thanks in advance!