"Recoil energy under 15#"

IMO this is the wrong way to put your question. Felt recoil should be the parameter. Recoil is a function of stock design, rifle and barrel weight, and the application of a muzzle break. I can promise you that a factory Savage or Remington rifle in .308 Winchester has more felt recoil than my 30-06.

There are also other parameter's such as bullet weight and velocity which affect recoil. If you shoot a similar weight bullet from a 30-06 and a 25-06 at the same velocity-then the recoil will basically be the same. Or so close that no one could tell the difference.

A 150 grain bullet from a reduced30-06 loadwould be deadly on deer to 300 yards. And even at a reduced velocity it would be easily asaffective or even moreaffective than a 100 grain bullet from a .243 Winchester(IMO).

I know a lot of people are going to say that the smaller caliber will have a flatter trajectory. And they would be right in saying that. However a couple of inches high at 100 leaves you a few inches low at 300. I do not want to do the exact math(but I am sure some one will), but there can not be more than a couple of inches difference at 300 yards. My 30-06 with 165 grain bullet is 2-1/2 inches high at 100 and about 5 inches low at 300 yards. I am sure that on paper that probably works out to more than 15# of recoil, it would be interesting to know what the felt recoil was.

Not for the sake of argument but I will take the "killing abilty" of the 165 grain 30 caliber bullet over the 100 grain .243 caliber bullet every day of the week, and twice on Sunday. Tom.