Anneal the Lazercast bullets by heating in a kitchen oven at 350 deg F, letting the thermostat cycle at least twice, then shut it off, leaving bullets in the oven to cool. When the bullets are cool to the touch, use immediately. Shoot them within 8 hours. If you have bullets left over which sit into the next day, anneal again.
I have never measured the hardness of any lazer cast that is is hard as they say. 16 bhn is the highest I've found. That is just a little too hard for best lapping, though it isn't real bad. They could be used as is.
Start with 2 grains, not 3. Better to stick a bullet and have to drive it back out than to have to clean out leading, which is certain if you use too much powder.
If barrel groove diameter is larger than cylinder throat diameter, the bottom of the grooves will not get lapped. You'll only clean up the rifling edges and tops of the lands, which is better than not doing anything with it. If your 454 is a Freedom Arms, you need to realize that they make their barrels oversize on purpose and haven't shown any desire to change in the 15 years or so that my customers have been complaining to them. They say they do it to reduce pressures, and because of their very precise barrel to cylinder alignment, they do get pretty good results with jacketed. However, this does not make a good cast bullet gun.
