I have been using 2018s since 1976 with my 55@28" K-mag,then 55@28" Howatt Hunter,then 57@28" Bob Lee and other limbs with my Lee 54 and 56 @ 28".I draw 28 1/2"+ and use 29" arrows they always worked.I have also shot them out of 49 lb. limbs and kinda heavy but still do not wobble.This year got a short riser Lee 53@28" and of course 2016s and 1916s and a Wal Mart cheap carbon work perfect.I would rather the little more wgt. with the 18s.Have not played with nock yet but will this evening.Any ideas would be helpful Thanks in advance.Kip