Here's two questions, since my knowledge is limited to only a few military firearms and maybe some Civil War ones ..
First queston: We have a gate with a couple of uniformed guards--highly trained and expecting trouble. What kind of guns would they have that would signal they're expecting trouble and want to be prepared?
Second question: There's a patrol boat guarding the shoreline. Patrol boat stops a fishing trawler that's gotten too near the shore. What kind of guns would the security patrol have?
In this case, the gate goes to a house owned by a member of the Royal Family. No one knows he's a member of the Royal Family, so the security is an oddity. A spy is trying to figure out who lives in the house. He sees first the patrol boat guards, and then the guard shack and is thinking, "Who is this person? These guards have a lot of firepower."
Thanks!
BTW--for your list in inaccuracies in books, there was one mentioned on these boards sometime ago about a book where the character inserted the bullets into the muzzle to load them.
It would all depend on the situation. Your setting is in the South Pacific, those are not normally considered 1st world countries meaning that what they purchase for their military or police is somewhat bargain basement. Kind of like a garage sale. That's only generalization. Here's one option that your fictional royal family might consider to equip their security forces:
http://www.angelfire.com/biz/troopsupport/
This is just one of the many companies out there that deal with military surplus. There are hundreds if not thousands of companies of all size.
As to what your security forces could be armed with, the range is huge. I'd imagine sidearms (go with a variation of the SIG as that seems to be what everyone is pushing for, lol) for the guards along with rifles or some kind of SMG (something in the HK family of subguns but if you go that route, make sure its compatible with the rest of the security force) or a combination of both.
What about a react force? Most if not all, royal families have a quick reaction force that is either used to suppress an aggressive hostile force or to support any emergency extraction of the principles. That react force would be heavily armed and armored, like SAWs, M203/M320 GLMs mounted on HK416s or maybe FN SCARs, and probably wearing Level III armor with ballistic plates. Don't forget sniper/spotter teams on the buildings in overwatch.
The cost of equipping a security force for a royal family is way more than a convention security unit. The major portions of that budget go to training and weapons. Training is the key. You could have them armed with single shot rifles as long as the training was high speed.
The patrol boat could be almost anything but the setting is the South Pacific so it won't be a harbor patrol boat but an ocean capable vessel meaning the size is larger therefore more crew and potentially more armaments.
If the security is tight, as it should be, anyone seeing that overt display of force and concentric rings of defense, and the alert status of the protective element, no matter how well trained they are, will pass on attempting to gain entrance.