Checking my unbuilt one again, it looks like the PMMA tank is about 2mm shorter than the barrel config. There's a 24mm glass section that might work better.
$1.69 Replacement Glass Tank for Orchid V4 RTA Atomizer at FastTech - Worldwide Free Shipping
I think I'd go with 1.5mm shorter than .5mm longer.
$1.69 Replacement Glass Tank for Orchid V4 RTA Atomizer at FastTech - Worldwide Free Shipping
I think I'd go with 1.5mm shorter than .5mm longer.