What is T6 7075 Aircraft Alloy material?
From Wikipedia: Aluminum alloy 7075 is an aluminum alloy, with zinc as the primary alloying element.

It is strong, with a strength comparable to many steels, and has good fatigue strength and average machinability, but has less resistance to corrosion than many other Al alloys.

Its relatively high cost limits its use to applications where cheaper alloys are not suitable.

Why it's hard to use T6 7075 to make Tight bore barrel?

Investment: R350.00

NOTE: The bore of this barrel is so tight around the BB that even the smallest obstruction in the barrel will cause a jam when fired.

This barrel is recommended ONLY for advanced/experienced players that take the responsibility to clean their barrels regularly in order to avoid jams.