Can grandparents get a deduction for contributions to grandkids 529's

[NCperson]

no -it's just a gift.......

remember only the earnings in the 529 create a tax benefit; funding the 529 in and of itself does not. 

[MikeinSC]

So, there can be a state deduction - there is in SC.  If you put money into grandkids' 529 (using the SC 529 plan), you do get this on your SC return.  Check your state instructions.