Saudi Arabia and Iran are about as different as you can get. Just to nitpick, have to because I speak Farsi.

Not because the Shi shipped a ship full of weapons to a backwater location no one cares about even on the east coast. On top of this, the only reason the the AK was even in DC was because it was sent by pre war china to arm saboteurs. Just because they are Asian doesn't mean they swear allegiance to China. Seriously, did you even look up the wiki on the Shi before you came here? The Shi are the original Institute before Fallout 4 even existed. Hell, they even make Vertibirds and Power Armor. They also do not manufacture ballistic weapons due to the monopoly by the superior weapons of the Gun Runners, they are a high tech faction who have long surpassed crappy knock off rifles that pre war China used. This is like saying Saudi Arabia is also Iran because the population share the same race. They are their own country, with zero control of the ghoul infantry in DC.

They are children of a SINGLE submarine crew who have long forgotten actual Chinese customs. The Shi don't have chinese assault rifles because they are not infantry. It just makes no sense why they didn't add the Chinese Assault Rifle in Fallout New Vegas. Plus, the Chinese could also have industry in San Francisco to build their own. They have an easier chance of trade by ship to San Francisco rather than sending ships around Asia and Europe/Africa to get to D.C. Which side would most likely have more Chinese Assault Rifles if you actually put thought to it? I'd say the Western US would end up having more.

on the east coast, then an entire major coastal city on the west coast. Think about it: China owns a facility in D.C. If the Enclave can fly, why can't Chinamen build scrap ships? Then with the increased supply, the Chinese ARs could easily be spread all over the west and become much cheaper. Some Chinese kids could mold the parts together with their teeth, then send the Chinese ARs onto ragtag scrap ships into San Francisco without any problems. I mean, I get that in Fallout 3, the Chinese have a secret facility set up in D.C., but in the west, they own San Francisco, which is a coastal city.

New vegas chinese assault rifle