After doing research for the last 2 years I found that the current ammo is that same that was produced in the '40's. It was 3200fps then and is the same now. They generally down load the ammo 10% "to be safe" in the old guns. I found by doing pressure readings that its not necessary. I have loaded mine to 3000fps and have 45-50,000 psi which is in the safe limits.
Apparently the biggest supply is in Africa and the weight is what kills most deals from what I understand.
Right now the biggest problem is brass cases.
but to every problem there is a solution