*Warning: this post contains unpublished load data. Use at your own risk.*
I've been casting for about a year now, reloading for eight, so I'm by no means experienced when it comes to the members on this board. I entered into much caution when I decided to cast for a Glock 22. And I mean straight up Glock 22; no drop in barrel, no coated bullets (those work too), stock everything.
I read SO much regarding the potential hazards whether it be case separations or leading in the poly whatever rifling. I ended up running some tests in a Glock 30 in 45 auto which I've been shooting with a drop in barrel. As far as I could tell, the only disadvantages to using the stock barrel were a 1% increase in brass loss due to overworking the case possibly because the Glock chamber is slightly larger than the drop in variety. Leading wasn't a problem using my locally sourced range scrap which I believe to be at around 11bhn on average.
For the 22, I chose the RCBS 10mm-170-SWC because it closely resembled the profile of the Hornady 180 gr FMJs I was using. I lubed them with RCBS' 80008 using a Lubamatic 2. I chose a seating depth of 1.157" to give enough clearance in the magazine while not being too deep to cause an unwanted rise in pressures. I have been using 5.4 gr. of Win Auto Comp for the 180gr. FMJ load (902 fps) and figured the lighter weight cast boolit would track only marginally faster with the same load.
So out to the range and 50 cast rounds later. Out of ten rounds I get an average velocity of 926, ES of 41, and a SD of 12. No leading. No Glock smile on the cases. No problems.
Its difficult to avoid the group think and to keep from echoing the masses. Besides, commercial cast bullets DID lead my barrel. It just so happens that a softer boolit fired at moderate velocity did not have the same result. Moral of the story: don't be afraid to test for yourself.