I like the way MidSouth does back orders. You place your order and they will hold you in line until they can fill it. it took 9 months to get Remington 7 1/2 primers, but when they came in, I got a call asking if I still wanted them - heck yes send them on! Midsouth handles Magtech and Remington brass in 357. Their selection is not as good as some places, but like I said I sure like the way they handle back orders, very good people to do business with. Another big house brand just sends out an e-mail and if you are not quick enough (I never was), you just loose out.
Good Luck and Good Shooting
BTW I never heard of Jamison brass either. I do understand that desperate feeling when you need some thing and can't get it, any port in the storm, but some times that port ain't so friendly.