Filling with a syringe requires 10cc of Tribolube/Christolube. Implying that a two ounce tube (60 cc) only fills two regs suggests that there is either a short fill of the tubes or lots of waste.
I buy Tribolube by the pound and fill my syringes manually. The newer tool by Scuba Instruments is superior to the Scubatools threaded delrin item, but I suspect that both leave tiny voids as they inject from the piston head end. The lube is just too viscous to flow evenly around all the spring nooks.
The convenience and ease of use of the Scuba Instruments syringe is HUGE. Malibu Diving in SoCal uses it and swears by it.
Me, I'm still a little suspicious, and I fill the piston/bullet/spring combo manually, and add tracks of lube to the inside of the body before piston insertion. My waste is approximately 2 cc, suggesting the total actual volume is around 8cc. It can be messy until you've done it a dozen times, but it's far less of a frustration than trying to force Christolube from a tube under pressure through that Delrin head and having the tube split. Ask me how I know.
If
@Wookie can't find his, you can have mine. But better still, get the Scuba Instruments syringe:
Scuba Testing Equipment and Tools - Atomic
Or even better, albeit slower, get a 10cc syringe and a blunt needle, and do it manually. You only have to do it once every three years anyway.