I have a tc renegade 50 Cal from when I was a kid barrel is hosed as it was when I got it. I found a company that makes a drop in barrel for these guns, I'd like to go with a 40 Cal 26" barrel. My first question is what rate of twist would you guys Go with? Second question is the barrel will come in the white, what coating would y'all go with. As of now I'm thinking a 1-18 twist, and either black ice all the metal or plum brown just the barrel. Also wanting to shoot the heaviest conical I can in this gun so that is what makes me think 1 in 18 twist.