Even some initial pushing of the slider will not save the slider from being hammered by the spear tail. In my hydropneumatic guns the water around the front section of spear is driven forwards by the spear tail seal as the spear is pushed forwards from behind after the releasing valve is opened. With the trigger pulled the line loops are freed before the spear begins to travel and the annular water column around the spear pushes the line slide forwards, but water leakage slows this rate of acceleration compared with the spear driving up from behind it and the spear tail stop soon slams into the rear of the slider. This all happens in milliseconds. The hydropneumatic where this does not
occur is the Aquatech 500 and its sister guns. The rear line hook will not release until the spear tail stop hits the slider, but the slider in this gun is very light and the gun is not overly powerful, although with multiple spear insertion strokes the gun can be highly charged.
Incidentally the mono shooting line shown here was that supplied with the gun, but I never used it and switched to nylon cord using the gun's second spear. As the gun did not receive a lot of use, it is rather heavy like an RPS-3 and does not float, the mono equipped spear was never needed.