I have never had any problems with any of the cast springs from Chambers, L&R, or Davis. I have also had a hundred or so cast for myself out of 5160 or 1095. never had any trouble as long as they were hardened and tempered correctly. when I bought any L$R locks or parts I always temper them again because I think they are too hard. I have made a lot of tumblers from scratch out of tool steel and sears out of 1075. Even mild steel is OK if you case harden them sufficiently. I never have made locks for anybody except myself. I would classify lock making as slave labor. I wouldn't make a lock for anybody for less than $2000.00
After first 4 or 500 it no longer is slave labor but it is labor intensive. I have posted my ideas
on lock making here and I won't belabor the point. Cast steel plates,cocks,hammers and frizzens
are OK but the mechanism or the "engine" as I call it is a specialized thing to me and I must
make sure I send out something that might stay together at least for one season.
Bob Roller