The 300 Win mag with more sectional density (heavier for caliber) and slower to open up would penetrate deeper.
Don't understand why anyone would use a suppressor and a short barrel on a supersonic hunting round...only need one shot or maybe two to kill the animal...and it makes alot of noise supersonic...and less performance.
Did the guide have a short barrel and a suppressor?
It's your choice and I certainly don't care what you use...but you don't have to change anything but a slower opening bullet with more weight...like a Barns 200 gr. So before you do an expensive build test the bullets in medium...the 180 gr Nosler against any bullet you use, like the 200 gr Barns against your 180 Nosler for wound channel and penetration.
I shot my last bull with the 7mm Remington Mag factory rifle 24" barrel, years ago with 175 gr Nosler looking for better bullet performance...all 4 Nosler partitions passed through the chest after I shot him 3 times ran down and he was still standing...looking at me as if to charge, reloaded and shot him again...he ran out of sight, before dropping. I went to the 338 win Mag, sold the 7mm mag yrs ago. Usually get huge exit wounds, when compared to years of hunting with a 7mm mag , alot of blood shot meat tiny exit wounds were standard..i
Bullets do not travel in straight lines when a bone is struck or a a side portion of bullet breaks off they go off course, sometimes sharply there by stopping exit wounds. The 175 7mm has more sectional density than a 180 308 compare the numbers...but do the experiment to find what works for your 300. If I went to 338 it would be at least 250 grs. for good penetration...mine shoots 275 gr at 2675 fps with RL 26 24" or a 416 Rigby with 400 gr. Barns at 2600 fps. 24" barrel, these heavy bullet calibers penetrate, but not needed..but on lighter big game you should definitely get exit wounds. I like exit wounds of the large size..softball to football size about right.