Bennie1986,
I haven't tried them but they have been talked about here on the forum before. Seem to me that they are very similar to Rainier bullets, which means you can use the data from your load books for lead bullets. At least that is what Rainier's web site recommends.
If they are similar to Rainier bullets you should be fine out of your .40, just treat them as you would loading any lead load and slowly work your way up to whatever velocity you are looking for.
Good luck and be safe.