Sports sticks and striking gear on a plane
At a US security checkpoint
TSA treats sports equipment that could be used to strike someone as checked-baggage equipment. Its item list marks baseball bats, cricket bats, golf clubs, hockey sticks, lacrosse sticks and bowling pins as unsuitable for carry-on. A padded sleeve does not turn a bat into a cabin item. If you need the equipment at your destination, arrange checked baggage before travelling to the airport.
Protect the head and check the case size
A golf club needs protection around its head, while a hockey blade or lacrosse head needs space so it is not bent or crushed. Secure the equipment inside its case rather than relying on the outer cover alone. Measure and weigh the case after packing. TSA's screening decision does not set your airline's sports-baggage allowance or price; check those with the carrier.
Pins, balls and other accessories
Bowling pins are solid striking objects even though they are not sticks. Pack them as a separate case from bowling balls and check each item you plan to bring. Balls, pumps and cleaning products can have different screening or dangerous-goods rules. These TSA answers apply to US checkpoints; for a flight departing elsewhere, check the authority and airline for that route.