I tuned with bare shafts according to the instructions on OL Adcock's website and the 2018's grouped as if they were to stiff. They grouped left of the fletched shafts and had a severe nock right attitude. The 2016's were much better. I wonder if my bow is mismarked. It is marked 60# @ 28" but I bought it new in 1984. It's not FF compatible, has dacron string and cat whiskers silencers. It feels every bit of 60+ to me after not shooting it for probably 5yrs.