If I could have only one gun period. The choice would be simple. It would be the 358 Winchester in a Browning BLR. You can shoot it right handed or left handed. I'm mostly a lefty, but ambidextrious.
For varmints that you just need out of your crops there are dozens of bullet molds or manufactured bullets intended for pistols ranging from 110 grains up to about 180. The 110s up to the 140s can be driven over 3,000 fps.
For edible small game 158 grain solids can be loaded down to 1,050 fps to stay subsonic.
For deer and antelope there are 180 and 200 grain bullets. These will go faster than the 308. The 180's will equal a 165 out of a 308 and the 200s will equal the 180s out of a 308.
For Elk, Moose and most of the larger African antelope the 225s can be driven at 2550. This shoots amazingly flat. Wth a 200 yard zero a 150 grain 7mm Mag started at 3,200 is 6 inches down at 300 yards. The 225s at 2550 out of a 20 inch barreled BLR is only down 10 inches at 300 yards.
If more penetration is needed the 250 grains bullets can be driven at 2,350 which is over 3,000 ft-lbs of energy at the muzzle and still delivering a long ton 2,200 ft-lbs at 200 yards.
For really big stuff there is the Swift 280 grain or the Woodlieigh 310 grain which comes in a soft point that still expands well at 200 yards or the 310 solid which has killed Elephant, Cape Buffulo, etc.
So you have your bases covered from squirls to elephants and everything in between. And it will do all that without painful recoil or hideous muzzle blast. Then there is efficiency. Most of my loads use between 45 and 52 grains of powder.
So there you have it. One gun to do it all. What would by second and 3rd choices be, well I'd have to go with the 350 Remington Magnum and the 35 Whelen. With the 357 pistol bullets thrown in you get a bullet weight range that run from 110 right up to 310 grains. Also wiht a little bit of accuracy loss 9mm bullets can be used taking the varmint end down to 85 grains.
The relatively small case lends itself to fairly light reduced loads while on the other end the performance is 7-8% behind the 35 Whelen using 15% less powder.
Every rifle the 358 Win has been chambered in was designe for pointed spitzer bullets with good to high Sectional Density and Ballistic Coefficient. Granted you lose that advantage when using pistol bullets for varminting.. But this can be larrgely overcome by velocities in the 3,100 to 3,200 fps range.
