What do you mean by geting them tuned in?. Does tuning it in consist of puting about 200 rounds through the gun to break it in, or by modifying the gas ports etc. Also i have another ? how do you figure out if you got the backwards gas setting selector, do you have to take it all apart to see what way the ports face. I thing if i get a s20 most likley i will only be shooting Remington 3" nitro mag 1 1/4 oz high brass, Or S&B 3" magnum low Brass, and maybe the ocasional 2 3/4 game loads. So if i set the gas seting to the correct seting for mags, what ever that may be, it should shoot fine r