Bumped for great justice.
9mm = Las Pistol
Handcannon = Bolt Pistol
Shotgun = Arbites Riot Gun
Hunting Shotgun = Unnamed ancient-pattern shotgun
Lever-Action Rifle = Unnamed ancient-pattern rifle
Bullpup = Lasgun
AK = Autogun
Flamethrower = Flamer
LAW = Missile Launcher
Machete = Entrenching tool
Axe = Arbites Shock Maul
Katana = Power Sword
Chainsaw = Chainsword
This list is pretty spot on but as some one who studdied into 40k lore for weapons..
Hunting Shotgun would be just a shotgun classified as a slug thrower.
"These come in a few styles; Pump Action, Assault and 'Sporting'. Assault are semi-automatic or fully automatic shotguns, and sporting shotguns are typical over/under or side-by-side double barreled shotguns."
Not only is the definition for the shogun broad as hell, meaning you can create your own designs and styles, the efinition for a slug thrower is even braoder.
With the LAR, same instance as above. It'de be a slug thrower - Rifle. Which is: " assault rifles, carbines, sniper rifles, and submachineguns."
The crossbow can be a needle gun, which is a form of alien sniper used mostly by the assasin guys. It sends out a small laser that penetrates armor ahead of the poison coated needles.
Alternativly the LAR could just be a Sniper Rifle. Not all snieprs are Long-las. Long-las are good because you don't need to adjust for windage/distance but traditional snipers are often used with suppressors to keep their position undisovered. Lasers are easily trackable where as bullets are not.
The knife can be just that, a knife. Most Space Marine Scouts are armed with a combat knife when using a bolt pistol so you could use that for the knife.
Power Sword? Hmm, I think a chain knife can be thrown in there without too much fuss.
The SCAR should be a Hotshot/Over Charged Las-rifle or a Hellgun.
The M32 can be the standard IG issue grenade launcher.
I read through most of the thread, msot of it's just been Space Marine (game) hating (I don't liek the game but don't bring it up like that plox), and player model stuff so I figured i'de throw my 2 cents into this.
I can think of it a bit more, I know there's alot better I could do to suggest but that's it for now.