Vent exactly where two fronts meet

Two end gates filling toward the centre with a 5mm vent placed on the meeting line. The witness line is cosmetic only and survives a 2 bar test.

Filling a 204mm thin section from one end. It misran at 140mm every time, even 10C hotter.

Spent a whole trial arguing about whether A413 fluidity was the problem. It was not. The metal was fine, it just had nowhere to push the air. Once the vent went on the meeting line the part filled on the first shot and has filled every shot since.