Ordered and received a 3-15X scope for the Grendel. Think I'll install it and adjust zero, then shoot a group or two, before fooling with barrel harmonics. I think it deserves a higher magnification than 10X.
I'll move the 1-10X to the 303 replacing an old beat up 3-9.
Also ordered a 6-24X (not yet received) that will probably end up on the 6.5 Swede or 7Mag. Both are capable of sub-MOA groups and shoot rather flat.