MP7s were used by SG-1 in 2006, whilst working undercover as "drug dealers" on P6G-452. They later used them again (apart from Mitchell, who carried the G36K) on Ba'al's Ha'tak vessel to retrieve the stolen Stargates. MP7s were also used to search and destroy Poole's Replicator. (SG1: "Off the Grid", SGA: "Outcast")
The MP7 was developed as a direct competitor to the ubiquitous FN P90 so famously used by SG teams since 2001. Its use is unusual in that, in head-to-head trials between the two, the 4.6x30mm round used by the MP7 was found to be significantly inferior ballistically to the 5.7x28mm round used by the P90.