Back in the day you were required to qualify every year if you were a courier or for carrying as aircrew, but it you shot E three years in a row you could keep the medal and wear it even if the qual lapsed like you went to shore duty or shot poorly every now and then. Kept a guy from having to remount his medals all the time.
OPNAVINST 3591.1E dated 20 Deb 2007 is the current instruction
http://doni.daps.dla.mil/Directives...0 Training and Readiness Services/3591.1E.pdf
It discusses range requirements, qualification sequence of fire, conversion from other service ranges, etc.
There are many different range quals. Some used to not be acceptable for shooting for score. But after 9-11 they allowed other service scores to be adjusted to enable ribbon / medal qualification. Basically you need to score 95% or better for E, 90% or better for S, and 85% or better for M, with 75% or better for watchstander.
Most commands I've been in recently have plussed up their NCEA (ammo allocation) to actually allow proficiency when shooting. We tryically shoot 9mm every other month. I also view it as senior officer therapy, so it serves multiple purposes of proficiency, stress relief, camaraderie, and wagering. We usually bet a beer per point of delta between two people's scores.
The best program is the NIACT course for IAs down at Fort Jackson. It is a 3 week total immersion course where you carry an M-16 and 9mm everywhere. They live fire, sim fire, zero weapons, and eventually qualify you on pop-up targets for the M-16. Once you zero your weapon, you will shoot until you qualify. Some guys take days, but almost everyone can qualify eventually, without lowering standards. And, you actually gain a comfort factor with the weapons, rather than feeling like Barney Fife. Down side is you get to use your new found proficiency "boots on the ground" in Iraq, HOA, or Afghanistan for a year.
Camp Allen Range at Norfolk is used for weapon qual, but it is also an MWR facility, so they rent guns and sell ammo for your personal use during specific times of the day. Not any different than the golf course, really. You can rent equipment or bring your own (must comply w/ specific safety & transportation regs, which vary by base). Often they require you to purchase ammo only from them - probably keeps people from using creative loads that they concoct on their own. They'll give you either a range safety brief and test, or you'll have to sit through the 20 minute safety lecture each time prior to shooting. If you shoot and pass the Navy Qual course, they'll give you the paperwork to verify your score to take back to your command.
On bases where they don't have a range, many commands have made arrangements w/ a local range to provide the same opportunity. If you think about it, it's a winner for both parties. The range gets more business and perhaps inspires someone to become a gun enthusiast, and the individual gets the eopportunity to possibly shoot for a ribbon or medal.
One other thing I saw recently but cannot remember where - USNA mids can wear Navy weapon qual ribbons. NROTC mids cannot wear the Navy Ribbon unless they were actually on Summer Training under paid orders when they qualified. Having said that, most units have their own "fruit salad" that has a Pistol Team / Rifle Team ribbon as an extra-curricular activity ribbon.