I had the same problem. Found 1 box locally. & someone sent me this link. https://lockedloaded.com/product/remington-ammunition-l38s2b-umc-38-special-jhp-125-gr-100box6case#product_detail
I placed an order with Midway on Dec 23rd. They had a limit of 2. So I ordered 2 gen 2s. 2 gen 3s & 2 20 rd. Received the gen 2s today. The other 4 are still back ordered.
The Herters Select brass sold by Cabelas is now mfg. by S&B. Looks identical. I was wondering why the boxes changed to the same size as Sellier & Bellot. & then I read the back.