5 pins where are you getting these bullets? (I am very interested in trying some)
As far as shooting light bullets in the 45, my Second Chance pin load was with 160gr swc lead, I was pushing them pretty hard 195 pf around 1225 to 1250 fps with a very fast powder (would not really recommend it to any body else) but I shot it for years at pins with no leading problems in schuman bbls. In the comped guns they worked great (LOUD) but great. took the pins rite off, as for loads all I can say is start low, watch the pressure signs, and I seem to recall that the lighter bullets in 45 were sensitive to oal and the crimp, be careful and don't blow yourself up.