Your ASA has what is known as a 15 degree outward angle to it. Also known as an "angled" asa. The only option is to purchase a straight one or have to do some magic and either reverse the one you have and route the wires for the noid through the hole which will be on the left side. Be sure that the reg doesn't interfere with the trigger guard and hopefully you have enough solenoid wire.
LACoFD Straight Streams Paintball