35 Rem is a easier to find components, and occassionally, ammo.
No factory ammo for 375 Winchester. I had two 375 guns and currently own a 35 Rem in 336SC. Sadly it sits in the safe as I found a 33ER (356 Win) two weeks ater I bought it.
The straight wall is easy to load. The larger diameter of the 375 does help on game.
The 35 Remington shines with the Speer 180 JFP.
