I am hoping to get my build going soon. I have been leaning toward a barrel length of 18.5" this will mainly be my deer hunting rifle. I hunt mostly mountain land so not a lot of long range shots maybe 250yd down in the bottom land. I plain on mainly shooting 165 and 168gr bullets. My question is what twist would you guys recommend for a stubby 18.5 barrel. It will be a bartlein rem/var contour. What kind of velocity can i expect going this short compared to a 20". Thanks