The difference between tensioned barrel vs non-tensioned barrel usually is the fine tune which boils down to harmonics. However on a full floating barrel I prefer no tension as it is easier to find the harmonic node. Both CAN be tuned to shoot 1/2 MOA with some work.
HOWEVER! You are getting 0.8 to over 1 inch at 58 yards which is well over MOA so you might want to work your tune and shooting system because regardless of tension or not you should be @ MOA or better before the comparison can begin. Half MOA is where you need to be without wind but at the very least you need to be under 1/2 inch at 50 yards, all FX guns are capable of minimum MOA unless the tune is not optimal.