Welcome aboard ! That rifle sounds familiar. Wait, I think I see it laying on that Elk below.
There are many calibers that will do what you want. Banging steel with your buds and culling does that 6 br with 105's or 107's would be hard to beat and so accurate you would be amazed. Plus the barrel life is great and the price to shoot it with top notch compoenents is very affordable. But for some of those bigger WT bucks you go after in northers MO. you would want to take the 30-378.
There is a thread on here about a rifle I am really looking forward to seeing. It is a 6.5 Sherman and you should read the thread. The guys that built it and own it are straight shooters. They are both members here I shoot with one of them quite a bit "BignGreen". His dad actually owns the rifle and as I understand it it has been in the family taking game for years. They recently rechambered it to this chambering. I am not sure it would be a great chouce for you for a steel pounder as I don't know what the barrel life expectancy is. But there are plenty on here that do. Anyway you should read about it a little.