I`m sorry ,but I`ve only loaded 9mm for a revolver & cycling was`nt an issue .
Reloader28 seems to have more exp with autos & gave a good explanation that seems to mirror alot of 9mm shooters .
My base source at the moment is isotope containers
this site will give ya a good explaination of the alloys used & lab tested levels of tin & antimony.
Alot of it over on http://castboolits.gunloads.com/
for `bout $1.00-$1.25/lb. delivered .
Some times according to supply ya may have to wait for a demand
I like it it comes very clean & ya know te alloy content so ya can controll the bhn & cost of alloys !