Needfreestuff ,
I did end up Tracking the Shelters at 1.70 grams which is a little lighter than Shelter's optimum midpoint recommendation .
All of the re-builds took from 6 to 10 weeks from the date I shipped until the day received . I always have a couple of Cartridges on hand just in case . If you don't have a back-up Cartridge , you could buy a used one here on the Gon to get you thru the wait .
Good luck