Like almost any scissor lift device there is a slight movement left to right but once your rifle settles into the bag and is supported with your shoulder shoulder or even better a good quality leather rear bag, I have found that the system is phenomenally stable. Before even with a good tripod and a stock bag, with my best efforts at 100 yards you could see the scope crosshairs move from left to right over a 1MO a Targets . With this system it is rocksolid, dead zero, no movement at all! Frankly I am amazed at the stability of this unit and the ease with which operates. Unlike another review I read mine is completely silent while being used. The large lineman match shooting bag and bag Jack are a great combination and once your rifle stock is nestled in that shooting bag, there is no movement unless you intentionally want it move. The large Lyman match shooting bag and bag Jack are a great combination and once your rifle stock is nestled in that shooting bag, there is no movement unless you intentionally want it moved. A great buy for the price and a great piece of equipment to add more results of 1/2 MOA target matches. The unit itself along with the bag has sufficient weight in itself but I have added an extra 3/8” 12 x 16 aluminum plate with adjustable spiked feet because of the shooting benches that are at the range are covered with carpet. The slightly wider footprint and the ability to level the unit on unlevel benches even adds to the accuracy convenience of use.