I did it like this, but the player doesn’t stop at the barrel and also just shoots upwards even if the barrel is in another position in the rotation
Hey @felipedistro! Welcome to the forums!
For this you will need to use “Get Actor Forward” from the barrel, multiply that by a float value, and plug it into the launch. You’ll need to recombine the pin for this, though! 
Also make sure the X axis points directly out of the front of the barrel actor- it should be sideways by default for this to work.
Hope this helps!
Hey @felipedistro!
Did you get it figured out? Let us know!