Pete - should be just fine, however, much depends on the powder charges you will be using, whether or not the hooked butt plate is going to be hard on the body. The heavier the better if using heavier charges for say, elk or moose.
1" seems to me to be quite small for anything larger than a .54. what will it weigh? I did not see a weight suggested, but 36" of barrel should help that out a bit.
The last rifle I built was in 2008. It was a "work in progress" when I got it.
It was a GM barrel,58 caliber and 1" across the flats. I shot it with 80 grains of
GOEX 3fg and a tight loaded .575 ball with striped pillow cloth patch and I got
good results at 260 yards shooting offhand at clay discs the shotgunners left around
after their Tuesday shoot.50 yards from a rest was a one ragged hole group.
I styled it after a Swiss "Stutzer" from 1805 cutting the barrel to 36" from 40"
Butt plate was almost flat and all steel trim and a Ketland lock that I made from
parts I had in a desk drawer for about 35 years.
Bob Roller