Are the bolts supposed to be self tappers as the new barrel has no thread?

I can see the kit includes the below. 4140 030 2000 - Piston Ø 34 mm 4137 034 3000 - Piston ring Ø 34x1.5 mm 9463 650 0807 - Snap ring 8x0.7 4137 034 1500 - Piston pin 8x5x22 9075 478 4268 - Pan head self-tapping screw IS-D5x60