Infinity, Unlimited maintains an armory that checks out firearms, mêlée weapons and body armor as is milieu-appropriate. There is also a commissary that can provide appropriate clothing and tools. However, no modification of weapons is allowed. All ISWAT equipment must be turned in at the conclusion of a mission. (which means it is not available for “unofficial” jaunts between worlds or for use on Homeline)
ISWAT members can purchase firearms, tools and other equipment for their personal collection and use. In fact, a group of enterprising ex-Patrolmen have set up a fairly lucrative business as registered firearms dealers who work on base. Most any weapon legal to be owned in the United States can be acquired for Infinity, Unlimited personnel use under an agreement with the United Nations and Canada. Dealers do have to be FFL licensed, and deliveries can take from three days to two weeks depending on the firearm being purchased. Firearms purchases are by special order only. Having said that, occasionally a Patrolman will purchase a firearm, be called away on a mission, and be killed in the line of duty, so the local dealer may have some interesting things on hand if speed is an issue.
Infinity, Unlimited customs agents do review everything a team brings back (if they can find it). Smuggling in off-world weapons may not be necessary if it’s an analogue to an existing Homeline modern or historical firearm. However, more exotic weaponry may be confiscated.
Customs doesn’t like magical items. Magical items are proof of having been on magical worlds, and magical worlds are by and large forbidden. (Magical mind reading endangers the Secret.)