[Llarry]

The U.S. military services have taken delivery of about 500 C-130J transports and specialized derivatives. The J model advanced Hercules has replaced earlier C-130 variants completely in the active Air Force and the Marine Corps and are closing in on the replacement of legacy C-130s in the Coast Guard. The Air Force Reserve and the Air National Guard have mixed forces of old and new aircraft; the Navy is the only service still without any J models.

The basic C-130J transport is only about one-third of the total USAF force with just over 100 C-130J-30s in service. (the J-30 is a stretch version). Many Air Force J models are Special Operations aircraft including:
-- MC-130J SpecOps transport -- 50+ aircraft
-- HC-130J SpecOps refueling aircraft - just over 20
-- AC-130J SpecOps gunship - about 30 aircraft
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The Air Force Reserve and Air National Guard are slowly transitioning to the new J models as production is funded. They also have some specialized models, including Reserve HC-130Js and the "hurricane hunter" WC-130J, of which 10 are operated only by the Reserves. A single Air National Guard unit flies EC-130J electronic jamming aircraft and the ANG also flies HC-130J refuelers. The ANG is also home to a single squadron of non-stretched C-130J transports; after that initial batch, all transport orders have been for the longer variant.

The Marine Corps has four full squadrons of KC-130J transport/ refuelers and is organizing a fifth squadron in Hawaii. It also has a couple of USMCR units receiving KC-130Js. The Marine KC-130J is the short version of the aircraft.

The Coast Guard is well along in replacing its older C-130s with new HC-130Js. Note that the Coast Guard HC-130J is not the same as the Air Force HC-130J; very confusing. The USCG wants 22 Js and has 17 so far.

Then there's the Navy, which has a requirement for 25 KC-130Js to equip five Naval Reserve squadrons, which have traditionally been transport units. Given that mission, I'd expect the Navy to want the stretched aircraft and not the Marine Corps shortie. The procurement of Navy aircraft is about to begin (if funding is approved), so we'll have to see what they come up with: Short? Long? Strictly transport or transport/refueler? Time will tell.

A future version for the Navy is a C-130J replacing the E-6B in the strategic communications role. Another designation issue would appear to be coming, as EC-130J is already in use. Again, time will tell.