I did this on High ground, I am not sure if it works elsewhwere. You need two people and a turret.

Have one person get on the turret and the other turn into ball mode (you can only do this on forge).

Then have the person who is the ball pick up the turret and ram it into the barrier, then just push the turret against the barrier without holdig the trigge, and it shoud be through!

You need to push for a few seconds.