Buy a barrel snake cleaning rope for your pistol. (I prefer one slightly over sized myself).
I've done both home done lead and missouri bullet company lead in my progressive.
Be a bit aware of shaving possibilities. As in, maybe add a bit more bell/flare to your case and make a more conscious effort to get the bullet vertical.
That's about it for loading concerns.
Shooting concerns - you'll have to work up a load that suits your gun. By suiting your gun, I'm referring to produces the least lead fouling.
It's by no means a linear graph for powder weight to fouling. Hell, it's a zig zag of a line.
Basically, load up a dozen rounds at a given powder weight. Change it by 0.1 or 0.2 grains and load up another dozen. Do this a few times so that you have, say, 5 or 6 loads to test. Hell, maybe even a dozen. Up to you.
Now that you have your loads boxed and labeled. Pack up your cleaning snake and head to the range.
1) make sure your barrel is clean (field strip and inspect)
2) shoot a couple rounds
3) inspect barrel, make note of condition. use a cell phone to take a pic maybe ?
4) shoot the rest of the rounds for that recipe
5) inspect / note / pic
6) run that cleaning snake through a bunch of times and get her clean.
7) switch loads and start over again
If you feel that your first magazine is at unfair (dis-)advantage, you could always make up two magazines of them and run them again at the end of your sessions to inspect again etc.
You'll note that things can be 'ugly', 'not so bad', 'purty', 'hideously ugly', 'not bad', 'hideously ugly', etc. Don't expect your results to make any sense.
At then end of a lead shooting day, I'll usually put a few plated rounds through in rapid succession and give'er a good snake'in quickly while things are hot.
You'll want something like:
Be careful with bluing though (it can be hard on it). You can also just get the paste and make your own etc etc etc.
But on a stainless gun, the above stuff is godly.