Mini UZI Polygonal Rifled Barrels

 

IMI made polygonal rifled barrels for the UZI to compete with the MP5 for the Secret Service contract but obviously was beat by the MP5.

Unlike the full size UZI, the INTERNAL dimensions of the semi and full auto trunions are the SAME.  IMI could have made the SEMI barrels with the secondary barrel band present on the SMG barrels but who knows why they didn’t do so.

As pictured below the SEMI barrel below will drop into a SMG trunion but without the barrel restrictor ring in place in the SMG receiver, there will only be one point of support as pictured below.

Pictured below a custom bushing is added to a ‘semi’ IMI Mini barrel to give the barrel two points of support in an SMG receiver that doesn’t have the restrictor ring.  If the receiver is a semi receiver with the restrictor ring in place, it will give the barrel 3 points of support.

Once the bushing is added, there will be two points of support as pictured below.

IMI Polygonal barrels turned down to accept the custom bushing:

After bushing is pressed on

After being press fitted, the barrels need to go back into the lathe to obtain the proper OD:

Barrels after parkerizing

Regarding the 3 lug, barrels were turned down and threaded almost the entire length to eliminate a ‘free bore’ condition which results in hard fouling inside the 3 lug adapter