I 'm looking at a 1:7 twist for my .243 winchester. What caliber will beat it at long range, say 300yds or more like 500 yds. Would it be wise to go to a better caliber such as 6mm BR, or 6mm-284? Right now I have a 1:10 douglass extra heavy bull. It shoots inch and a quarter at 300 with a 87 v-max.

Savage- barrels.com.... how is the quality?