This reamer holder is unique in that you can dial  in the pilot to enter the bore of the barrel by adjusting the three thumb screws. Once dialed in the reamer is supported for no drag withdraw and plunge of the reaming operation. The tension springs give a constant force to the reamer to stay  seated on the dead center in the tail stock. The holder comes with the dead center.

     The greatest advantage is the 360 deg. hold on the reamer. Ever try to tap a straight hole by turning and holding onto one handle of a tap handle? The same thing happens when reaming. The reamer tips 90 degs. of applied pressure and the pilot rides hard on the top side of the rotating bore.

     Radial alignment  is corrected with this reamer holder. Axial alignment is not. The axial displacement in the ram of the tailstock will provide what is needed. That is if the correct alignment procedure has been preformed to the lathe and tailstock for reaming operations, i.e. chambering for rifles! Tailstock alignment procedure for turning a true shaft IS NOT the same thing and will never give you true center lathe axis thrust for chamber reaming!

    Helpful hint: If you don't know how, or  your tailstock simply can't be realigned, then one of the manufactured floating reamer holders on the market is what you will need to purchase to correct axis misalignment and give you the ability to ream straight chambers.  But, on a floating reamer holder, nothing guides the back of the reamer, it goes where it wants. If the reamer starts crooked, it stays crooked, no matter how the barrel is lined up. It's up to you, my system where you know you're straight, or the others where you hope you're straight.

     The reamer is supported and aligned for dead center engagement into the bore.

TAILSTOCK ALIGNMENT FOR REAMING VIDEO

     As mentioned above, there is a required alignment procedure for tailstocks. Along with this , to achieve repeatability when moving the tailstock for  depth of cut , like head space readings, the tailstock has to come back into axial alignment when slide back up the barrel for resuming the reaming operations.

     This video shows how to dial in the tailstock along with the why the turning of a shaft for alignment is fighting and ruining all your efforts for flawless precision in the chamber reaming  operation.   50 minutes.