You've got to be kidding! To one who is accustomed to the 30/30 the noise and recoil of a 300 mag is like comparing the 30/30 to a .22 rimfire--- well no, its actually more than that. If you're thinking of getting one I'd suggest you first borrow one and run a box of shells through it and then see if you still want one.
Back when I was young and stupid versus my current status of old and forgetful, I fell for Elmer Keith's notion that the .338 Win Mag was a good beginners elk rifle, you know, before working up to a REAL elk rifle like a .375 H&H. I ran a lot of 275 grain Speer through an M-70 Winchester and a lot more 350 and 400 grain .458s through a Ruger #3 with max handloads and all of my shooting then was from prone! Well now that I've gotten old and scrawny I don't care to get kicked around that much and fortunately I've learned I don't have to. I'd likely feel differently if I ever encountered an enraged Grizzly or polar bear, but since both are pretty scarce in Colorado I feel no need for anything more than the 6.5X55 with 140 grain bullets at most.