i am going to have a 243 winchester built for long range off a rem 700 bdl. distances for 600-1000yards and long range deer hunting. plan is to use from 95gr berger vlds to 107smk sand 115 gr dtacs,whichever works best). what do you all recomend for twist and barrel length. i am interested in the broughton 5c barrels, does anyone have suggestions for makers of 6mm barrels? thanks.