225-70-rn 225299 question

I’m looking into this mold and had a few questions for the folks that are already casting and reloading for their .223/5.56 applications.
I have a 1/9 twist barrel ( 16 inch in length) and from what I’ve read, a 70 grain boolit will be very effective. Anyone else using this for a 1/9 twist? Are you powder coating and or using a gas check?
Since I’m new with casting and do not have enough knowledge was under the impression the fps velocities generated for the .223 caliber were too high without having leading problems. Can someone please educate me with some loads and or velocities your getting. What works and what was not?
Thank you for taking the time and sharing your information.
I was not looking for hot loads, however just a decent practice load possibly using a plain base, powder coated would be my first choice.
I love my ruger 204 and the .223 caliber but just always thought those were off limits for casting. Can someone give some experiences and suggestions please. Thank you and have a good day folks.