http://www.thefirearmblog.com/blog/2018/02/01/usw-320/Building on the success of their original Universal Service Weapon (USW) pistol, Swiss firearms and suppressor manufacturer B&T has designed a new polymer version based on the P320. Besides the modularity of the new USW-320, the frame itself is imported and sold as an uncontrolled part – meaning customers will be able to to buy it simply as a part or accessory and either add their existing P320 fire control group or purchase a new group through a licensed dealer.
Of course, prior to dropping a P320 fire control group into the USW-320 frame with a stock, owners will need to complete an ATF 5320.1 Form 1 – Application to Make an NFA Item – pay the $200 “making” tax and wait for approval. The upside of this process is that without the stock, the USW-320 with the fire control group is just considered a pistol that can be used prior to receiving your Form 1 and tax stamp. In addition, B&T has made the NFA engraving process easier by providing a suitable place for the required markings on the frame rather than directly on the fire control group.
This would work with an M17 and DPP MRDS as well.