Upvote:1
Generally speaking air rifles are allowed in checked baggage, but special precautions need to be taken - usually including special packing and making sure the cylinder is fully discharged. You may need to notify the airline in advance, and turn up early to check your baggage in. Check with your airline for what you need to do.
You should also check what permits etc. are required for importing and owning a PCP airgun in Indonesia. Many countries require them to be licensed.