Would like to get more info with the barrel tensioning ..I went all out with my m3 in terms of upgrades in fact it was shooting lights out out of the box.. but after fixing the TRS with the clamp and barrel tensioner the accuracy dropped ...removed every thing and just running the barrel holder ...and surprisingly the groups got tight again.. I am running a 700mm barrel is it really required for this barrels ..or it works for the longer 800mm barrel