I am thinking of building a long range hunting rifle.It would be used on Elk,Mule deer ,antelope,whitetails etc.I am looking at either a 6.5 weatherby or a 7 mm weatherby.In the 6.5 140 gr bullets would be used.In the 7mm 168gr bullets would be used.Which one would you go with and why? I have used the 7mm on game but never the 6.5.How would it do on game the size of elk at long range? Thanks