5.56 x 45mm die-cast Drill/Dummy
These dummy/drill rounds are die-cast using what appears to be a zinc based alloy. The hole through the body is 6mm diameter by 34mm deep. There are two shallow grooves, each 1.25mm wide, around the body.
These would be very cheap and simple to manufacture as the die-casting is a single, rapid, operation. There are no signs of any machining operations undertaken after casting, just minor clean up of “flash” at the mould line on some.
Who made these and who were they made for please?