dave: good for you. Now, one thing I do know about the 450 is that it can be handloaded to 45-70 specs (if you want some easier shooting) and some of those 45-70 loads are postively fun to shoot. With that being said, I have 3 Winnie Big Bores and all in 444. With heavy 300 gn loads, my long barrel (26") is no more difficult to shoot than my 06. BTW, none of my Winnies wear recoil pads - I just wear a PAST Recoild Shield whenever I take them to the range.
Rifle #2 is a traditional rifle - acutally, it is a Black Shadow with a pistol grip stock converted to a traditional rifle and man, does she shoot like a dream. Yes, they kick but with the PAST shield I can go through a couple of boxes of ammo until my jaw gets more tired of the pounding than my shoulder does. rifle #3 is a Timbe Carbine and with those ports on the end of the barrel she is rel easy to shoot - less recoil than either #1 or #2 rifle, but loud.
I would hazard a guess that the recoil from the 450 Timber Carbine with a proted barrel is about the same as my Triple 4 with heavy loads, and it isn't all that bad. Once you get off the bench, it gets much easier. If you are going to shoot yours with open sights first, make certain that front sight blade is short enough to get you on paper. When I first bought my Triple 4 Timber Carbine, factory loads were a foot low at 100 yds. Two lower front sight blades later from the Winchester parts people and now my heavy 300 grainers are on the mark at 100 yds with the rear sight at half mast. I had to drop from a .294" to a .264" and then to a .245" high front sight to get poi to poa.
One thing I did to increase my enjoyment of my Timber Carbine was to load up a bunch of slow heavy bullets for plinking - 10 grains of Unique under a 300 gn cast swc with a pinch of fiber bat to hold the powder in place and I was having fun levering those big long shells in and out like pistol rounds. I think that once hunting season has drawn to a close I am going to find am accurate low range loading for the 444 just so I can play with it.
Sorry I rambled so much but I hope I answered your question. I wouldn't be scared of that recoil at all - just be careful shooting in low light, as those ports will put a serious bind on your night vision (lol). HTH. Mikey.