.358 Win is the answer.
Uh... what was the question?
You can't make speed without pressure, but you can make pressure without speed. Just sayin'.
Careful ,Jeff...
(And this is not meant confrontationally).....Light Magnum and High Energy Ammo manage it....and you can increase speed at permissible pressure with the correct combo of good barrel,proper throating,correct barrel dimension,the right bullet,etc.It all has to do with diminishing,within limits,the resistance the bullet encounters in passage down the bore.Yes, it takes pressure for sure to make a bullet go fast...
But certain small factors accumulated in the aggragate,can result in two rifles giving significantly different velocities at the same pressures, or close enough that you won't blow yourself up
Tellya what,as an experiment....slug the factory barrel on your Sendero 300 win mag;we can see what it measures for comparison later;do load workup,chronograph, etc.Then let the throat out so that you can seat the 180 even with the base of the neck,in proper relation to the lands(your Remington action is long enough).Do your load workup again,and see where you are.
Then...replace the factory barrel with a Krieger stainless,same length,but have them cut it with a 309 groove diameter(yes it will still shoot)
....................have it throated "long";do load work up and we will talk as you go through it.I guaranty you will find out some stuff you didn't know before about the 300 WM....
And before you ask the answer is "yes" I have done all of the above,several times over,in calibers from 270 to 375H&H;years ago.Results are surprising...remember that the entire barrel is the "combustion chamber"....this kinda stuff will convince you that there are such things as "slow" barrels and "fast" barrels.
