[Jeff Higgins]

The 6.5 sure is the current darling, isn't it? I remember a time when the gun companies could give away a 6.5 anything to American shooters. Those of us who discovered the various 6.5's years ago had our own little secret for quite some time.

Truth be told, there is nothing special about that particular bore size. It succeeds partly for the same reasons the .270 succeeded - it offers less recoil (than the .30'06). Beyond that, it has traditionally been rifled with a very fast twist with which to stabilize heavy for caliber bullets. This gains two notable advantages - outstanding penetration on game with the right bullets, or outstanding long range performance with suitable bullets. It does nothing that other bore sizes are not capable of doing, so long as they are rifled with a properly fast twist and shoot their own heavy for caliber bullets.

For example, it is quite incorrect to say the 6.5 has less wind drift than a .30 caliber. Shooting bullets with the same ballistic coefficient at the same velocities, they will perform identically. Nothing is free, however - that .30 caliber will have substantially more recoil, through its far heavier bullet, than the 6.5. In the same weight rifle...

And that is where the 6.5 has come in. Each and every competitive rifle shooting sport of which I am aware restricts rifle weight. So, if all one has to do is hit a target, and we really don't care how hard, there is no reason to punish ourselves with a .300 Winchester Magnum shooting 220 grain bullets when we can get the same trajectory and wind drift with a 6.5 shooting 140 grain bullets.

Speaking of wind drift - it is a function of deceleration, not velocity. For any given bore size, we have a choice of lighter bullets we can drive faster or heavier bullets that will necessarily have to be driven slower. The heavier bullet, with a higher ballistic coefficient, will drift less in any given wind than the lighter, faster (initially) bullet. At some point downrange, the heavier, higher B.C. bullet will actually overtake the velocity of the lighter bullet that started faster. 300, 400, 500 or more yards - somewhere out there - the heavier bullet is going to retain more velocity. It will have decelerated less.