PMC Bronze is probably the weakest factory load that is still of decent quality and not difficult to find, while also being quite economical.
I've also tried some ATS X-Force M193 before that was probably as weak as PMC Bronze, though PMC Bronze is much easier to find.
The various steel cased ammo (Tula, WPA, WMC, Wolf Polyformance) are also quite weakly loaded, but pretty hard to find these days it seems.
Bookmarks