Two Problems With Piston

Hey guys so we are using a linear puncher with a slip/skip gear. We have three motors connected to it. We are having to problems. 1) The stopper we are using is simply a C channel hitting a Ch channel with lots of mesh in between. This is still causing a lot of shock witch is causing the robot to move towards the back left wheel. Do you have any sugesstions to how we can reduce shock while still keeping the current stopper? 2) The second problem is that for some unknown reason the piston is shooting about 7-10 degrees to the left. I think there may be a chance that the two problems are connected. I think it could be that because the robot is moving off to the right backwards it is causing the ball to go left. Thanks so much for your help, please tell me what you think.

On the first iteration of our catapult, we took the tires of the small rubber wheels and put them around our c-channel. Also, we used the c-channel inserts to give it resistance against against bending. To figure out the solution to the second problem, try holding your robot in place with your hands when you shoot and it can tell you if that is the problem. If so, adding a shock absorber will reduce the amount it recoils, which will help, and also strategic placement of batteries and adding weight to your robot will also help.

Can you put a picture of the whole setup of the robot, also you could try guides on the sides of where the ball sits.