I don't want a metal barrel, on this or any tank. It's unnecessary weight and strain on the elevation. They were originally used on static kits as aftermarket items because modelers had a tough time with seams of a two piece styrene barrel. Then DML started releasing kits with aluminum barrels and PE as a perk, which other companies followed, including Tamiya.
My two Tamiyas with styrene barrels ran 10 years without stressing the ABS elevation arm. Every model since them has been released with aluminum and what do you get? A need to replace the elevation arm and a barrel that needs a special primer. I'd rather spend an extra hour taking care of the seam on a styrene. If I could buy an aftermarket styrene barrel for the
JS-2, Pz IV and Panther I'd jump on it.