Can anyone provide a source for 270+ glass bead blast media other than Brownells? I have some ordered but it has been backordered for over 2 months. When I contacted them this week they were unable to tell me when it will be in stock/shipped. I need this to finish a pending project.
Thanks in advance.

Grainger or search ebay for glass bead media. Note that the Grainger 170-325 is extra fine media, I found it to be too fine, but I'm sure it is about the same as Brownells 270+.

Try Grainger or Florida Silica Sand. Also my local Harbor freight had glass beads, but I don't recall the particulars. For the amount you need, you might also call a local machine shop for a "loan". When I sold abrasives, hobbyists were always stopping by wishing to purchase 5-10 pounds when my smallest was 35#. I would invite them back to my blast cabinet and they could take what they needed out of the opened (and resealed) containers if I had something they could use.