Before you assemble your new CPT, go and grab yourself a 6mm tap and finish the threading procedure that did not get completed by the factory, on that knob that locks down the tilt feature(tilt or rotation, can’t remember as it’s been awhile).
The threads were never tapped completely thru which is why you’ll have the problem that Ezana4CE describes.
And to anyone still questioning the quality of this piece, don’t question, buy it. It truly is well made and the fact that I can use it to clamp onto my pcp’s in either the standard horizontal position or upright with muzzle up for maintenance and service work, it’s just one of those tools you should have in your arsenal.